sys/netinet6/ip6_output.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipsec.h"
  69
  70 #include <sys/param.h>
  71 #include <sys/kernel.h>
  72 #include <sys/malloc.h>
  73 #include <sys/mbuf.h>
  74 #include <sys/errno.h>
  75 #include <sys/priv.h>
  76 #include <sys/proc.h>
  77 #include <sys/protosw.h>
  78 #include <sys/socket.h>
  79 #include <sys/socketvar.h>
  80 #include <sys/ucred.h>
  81
  82 #include <net/if.h>
  83 #include <net/netisr.h>
  84 #include <net/route.h>
  85 #include <net/pfil.h>
  86
  87 #include <netinet/in.h>
  88 #include <netinet/in_var.h>
  89 #include <netinet6/in6_var.h>
  90 #include <netinet/ip6.h>
  91 #include <netinet/icmp6.h>
  92 #include <netinet6/ip6_var.h>
  93 #include <netinet/in_pcb.h>
  94 #include <netinet/tcp_var.h>
  95 #include <netinet6/nd6.h>
  96
  97 #ifdef IPSEC
  98 #include <netipsec/ipsec.h>
  99 #include <netipsec/ipsec6.h>
 100 #include <netipsec/key.h>
 101 #include <netinet6/ip6_ipsec.h>
 102 #endif /* IPSEC */
 103
 104 #include <netinet6/ip6protosw.h>
 105 #include <netinet6/scope6_var.h>
 106
 107 static MALLOC_DEFINE(M_IP6MOPTS, "ip6_moptions", "internet multicast options");
 108
 109 struct ip6_exthdrs {
 110         struct mbuf *ip6e_ip6;
 111         struct mbuf *ip6e_hbh;
 112         struct mbuf *ip6e_dest1;
 113         struct mbuf *ip6e_rthdr;
 114         struct mbuf *ip6e_dest2;
 115 };
 116
 117 static int ip6_pcbopt __P((int, u_char *, int, struct ip6_pktopts **,
 118                            struct ucred *, int));
 119 static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
 120         struct socket *, struct sockopt *));
 121 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
 122 static int ip6_setpktopt __P((int, u_char *, int, struct ip6_pktopts *,
 123         struct ucred *, int, int, int));
 124
 125 static int ip6_setmoptions(int, struct ip6_moptions **, struct mbuf *);
 126 static int ip6_getmoptions(int, struct ip6_moptions *, struct mbuf **);
 127 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 128 static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
 129         struct ip6_frag **));
 130 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 131 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 132 static int ip6_getpmtu __P((struct route_in6 *, struct route_in6 *,
 133         struct ifnet *, struct in6_addr *, u_long *, int *));
 134 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 135
 136
 137 /*
 138  * Make an extension header from option data.  hp is the source, and
 139  * mp is the destination.
 140  */
 141 #define MAKE_EXTHDR(hp, mp)                                             \
 142     do {                                                                \
 143         if (hp) {                                                       \
 144                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 145                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 146                     ((eh)->ip6e_len + 1) << 3);                         \
 147                 if (error)                                              \
 148                         goto freehdrs;                                  \
 149         }                                                               \
 150     } while (/*CONSTCOND*/ 0)
 151
 152 /*
 153  * Form a chain of extension headers.
 154  * m is the extension header mbuf
 155  * mp is the previous mbuf in the chain
 156  * p is the next header
 157  * i is the type of option.
 158  */
 159 #define MAKE_CHAIN(m, mp, p, i)\
 160     do {\
 161         if (m) {\
 162                 if (!hdrsplit) \
 163                         panic("assumption failed: hdr not split"); \
 164                 *mtod((m), u_char *) = *(p);\
 165                 *(p) = (i);\
 166                 p = mtod((m), u_char *);\
 167                 (m)->m_next = (mp)->m_next;\
 168                 (mp)->m_next = (m);\
 169                 (mp) = (m);\
 170         }\
 171     } while (/*CONSTCOND*/ 0)
 172
 173 /*
 174  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 175  * header (with pri, len, nxt, hlim, src, dst).
 176  * This function may modify ver and hlim only.
 177  * The mbuf chain containing the packet will be freed.
 178  * The mbuf opt, if present, will not be freed.
 179  *
 180  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
 181  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 182  * which is rt_rmx.rmx_mtu.
 183  *
 184  * ifpp - XXX: just for statistics
 185  */
 186 int
 187 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 188     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 189     struct ifnet **ifpp, struct inpcb *inp)
 190 {
 191         struct ip6_hdr *ip6, *mhip6;
 192         struct ifnet *ifp, *origifp;
 193         struct mbuf *m = m0;
 194         struct mbuf *mprev = NULL;
 195         int hlen, tlen, len, off;
 196         struct route_in6 ip6route;
 197         struct rtentry *rt = NULL;
 198         struct sockaddr_in6 *dst, src_sa, dst_sa;
 199         struct in6_addr odst;
 200         int error = 0;
 201         struct in6_ifaddr *ia = NULL;
 202         u_long mtu;
 203         int alwaysfrag, dontfrag;
 204         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 205         struct ip6_exthdrs exthdrs;
 206         struct in6_addr finaldst, src0, dst0;
 207         u_int32_t zone;
 208         struct route_in6 *ro_pmtu = NULL;
 209         int hdrsplit = 0;
 210         int needipsec = 0;
 211 #ifdef IPSEC
 212         struct ipsec_output_state state;
 213         struct ip6_rthdr *rh = NULL;
 214         int needipsectun = 0;
 215         int segleft_org = 0;
 216         struct secpolicy *sp = NULL;
 217 #endif /* IPSEC */
 218
 219         ip6 = mtod(m, struct ip6_hdr *);
 220         if (ip6 == NULL) {
 221                 printf ("ip6 is NULL");
 222                 goto bad;
 223         }
 224
 225         finaldst = ip6->ip6_dst;
 226
 227         bzero(&exthdrs, sizeof(exthdrs));
 228
 229         if (opt) {
 230                 /* Hop-by-Hop options header */
 231                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 232                 /* Destination options header(1st part) */
 233                 if (opt->ip6po_rthdr) {
 234                         /*
 235                          * Destination options header(1st part)
 236                          * This only makes sense with a routing header.
 237                          * See Section 9.2 of RFC 3542.
 238                          * Disabling this part just for MIP6 convenience is
 239                          * a bad idea.  We need to think carefully about a
 240                          * way to make the advanced API coexist with MIP6
 241                          * options, which might automatically be inserted in
 242                          * the kernel.
 243                          */
 244                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 245                 }
 246                 /* Routing header */
 247                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 248                 /* Destination options header(2nd part) */
 249                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 250         }
 251
 252         /*
 253          * IPSec checking which handles several cases.
 254          * FAST IPSEC: We re-injected the packet.
 255          */
 256 #ifdef IPSEC
 257         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
 258         {
 259         case 1:                 /* Bad packet */
 260                 goto freehdrs;
 261         case -1:                /* Do IPSec */
 262                 needipsec = 1;
 263         case 0:                 /* No IPSec */
 264         default:
 265                 break;
 266         }
 267 #endif /* IPSEC */
 268
 269         /*
 270          * Calculate the total length of the extension header chain.
 271          * Keep the length of the unfragmentable part for fragmentation.
 272          */
 273         optlen = 0;
 274         if (exthdrs.ip6e_hbh)
 275                 optlen += exthdrs.ip6e_hbh->m_len;
 276         if (exthdrs.ip6e_dest1)
 277                 optlen += exthdrs.ip6e_dest1->m_len;
 278         if (exthdrs.ip6e_rthdr)
 279                 optlen += exthdrs.ip6e_rthdr->m_len;
 280         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 281
 282         /* NOTE: we don't add AH/ESP length here. do that later. */
 283         if (exthdrs.ip6e_dest2)
 284                 optlen += exthdrs.ip6e_dest2->m_len;
 285
 286         /*
 287          * If we need IPsec, or there is at least one extension header,
 288          * separate IP6 header from the payload.
 289          */
 290         if ((needipsec || optlen) && !hdrsplit) {
 291                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 292                         m = NULL;
 293                         goto freehdrs;
 294                 }
 295                 m = exthdrs.ip6e_ip6;
 296                 hdrsplit++;
 297         }
 298
 299         /* adjust pointer */
 300         ip6 = mtod(m, struct ip6_hdr *);
 301
 302         /* adjust mbuf packet header length */
 303         m->m_pkthdr.len += optlen;
 304         plen = m->m_pkthdr.len - sizeof(*ip6);
 305
 306         /* If this is a jumbo payload, insert a jumbo payload option. */
 307         if (plen > IPV6_MAXPACKET) {
 308                 if (!hdrsplit) {
 309                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 310                                 m = NULL;
 311                                 goto freehdrs;
 312                         }
 313                         m = exthdrs.ip6e_ip6;
 314                         hdrsplit++;
 315                 }
 316                 /* adjust pointer */
 317                 ip6 = mtod(m, struct ip6_hdr *);
 318                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 319                         goto freehdrs;
 320                 ip6->ip6_plen = 0;
 321         } else
 322                 ip6->ip6_plen = htons(plen);
 323
 324         /*
 325          * Concatenate headers and fill in next header fields.
 326          * Here we have, on "m"
 327          *      IPv6 payload
 328          * and we insert headers accordingly.  Finally, we should be getting:
 329          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 330          *
 331          * during the header composing process, "m" points to IPv6 header.
 332          * "mprev" points to an extension header prior to esp.
 333          */
 334         u_char *nexthdrp = &ip6->ip6_nxt;
 335         mprev = m;
 336
 337         /*
 338          * we treat dest2 specially.  this makes IPsec processing
 339          * much easier.  the goal here is to make mprev point the
 340          * mbuf prior to dest2.
 341          *
 342          * result: IPv6 dest2 payload
 343          * m and mprev will point to IPv6 header.
 344          */
 345         if (exthdrs.ip6e_dest2) {
 346                 if (!hdrsplit)
 347                         panic("assumption failed: hdr not split");
 348                 exthdrs.ip6e_dest2->m_next = m->m_next;
 349                 m->m_next = exthdrs.ip6e_dest2;
 350                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 351                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 352         }
 353
 354         /*
 355          * result: IPv6 hbh dest1 rthdr dest2 payload
 356          * m will point to IPv6 header.  mprev will point to the
 357          * extension header prior to dest2 (rthdr in the above case).
 358          */
 359         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 360         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 361                    IPPROTO_DSTOPTS);
 362         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 363                    IPPROTO_ROUTING);
 364
 365 #ifdef IPSEC
 366         if (!needipsec)
 367                 goto skip_ipsec2;
 368
 369         /*
 370          * pointers after IPsec headers are not valid any more.
 371          * other pointers need a great care too.
 372          * (IPsec routines should not mangle mbufs prior to AH/ESP)
 373          */
 374         exthdrs.ip6e_dest2 = NULL;
 375
 376         if (exthdrs.ip6e_rthdr) {
 377                 rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
 378                 segleft_org = rh->ip6r_segleft;
 379                 rh->ip6r_segleft = 0;
 380         }
 381
 382         bzero(&state, sizeof(state));
 383         state.m = m;
 384         error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
 385                                     &needipsectun);
 386         m = state.m;
 387         if (error == EJUSTRETURN) {
 388                 /*
 389                  * We had a SP with a level of 'use' and no SA. We
 390                  * will just continue to process the packet without
 391                  * IPsec processing.
 392                  */
 393                 ;
 394         } else if (error) {
 395                 /* mbuf is already reclaimed in ipsec6_output_trans. */
 396                 m = NULL;
 397                 switch (error) {
 398                 case EHOSTUNREACH:
 399                 case ENETUNREACH:
 400                 case EMSGSIZE:
 401                 case ENOBUFS:
 402                 case ENOMEM:
 403                         break;
 404                 default:
 405                         printf("[%s:%d] (ipsec): error code %d\n",
 406                             __func__, __LINE__, error);
 407                         /* FALLTHROUGH */
 408                 case ENOENT:
 409                         /* don't show these error codes to the user */
 410                         error = 0;
 411                         break;
 412                 }
 413                 goto bad;
 414         } else if (!needipsectun) {
 415                 /*
 416                  * In the FAST IPSec case we have already
 417                  * re-injected the packet and it has been freed
 418                  * by the ipsec_done() function.  So, just clean
 419                  * up after ourselves.
 420                  */
 421                 m = NULL;
 422                 goto done;
 423         }
 424         if (exthdrs.ip6e_rthdr) {
 425                 /* ah6_output doesn't modify mbuf chain */
 426                 rh->ip6r_segleft = segleft_org;
 427         }
 428 skip_ipsec2:;
 429 #endif /* IPSEC */
 430
 431         /*
 432          * If there is a routing header, replace the destination address field
 433          * with the first hop of the routing header.
 434          */
 435         if (exthdrs.ip6e_rthdr) {
 436                 struct ip6_rthdr *rh =
 437                         (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
 438                                                   struct ip6_rthdr *));
 439                 struct ip6_rthdr0 *rh0;
 440                 struct in6_addr *addr;
 441                 struct sockaddr_in6 sa;
 442
 443                 switch (rh->ip6r_type) {
 444                 case IPV6_RTHDR_TYPE_0:
 445                          rh0 = (struct ip6_rthdr0 *)rh;
 446                          addr = (struct in6_addr *)(rh0 + 1);
 447
 448                          /*
 449                           * construct a sockaddr_in6 form of
 450                           * the first hop.
 451                           *
 452                           * XXX: we may not have enough
 453                           * information about its scope zone;
 454                           * there is no standard API to pass
 455                           * the information from the
 456                           * application.
 457                           */
 458                          bzero(&sa, sizeof(sa));
 459                          sa.sin6_family = AF_INET6;
 460                          sa.sin6_len = sizeof(sa);
 461                          sa.sin6_addr = addr[0];
 462                          if ((error = sa6_embedscope(&sa,
 463                              ip6_use_defzone)) != 0) {
 464                                  goto bad;
 465                          }
 466                          ip6->ip6_dst = sa.sin6_addr;
 467                          bcopy(&addr[1], &addr[0], sizeof(struct in6_addr)
 468                              * (rh0->ip6r0_segleft - 1));
 469                          addr[rh0->ip6r0_segleft - 1] = finaldst;
 470                          /* XXX */
 471                          in6_clearscope(addr + rh0->ip6r0_segleft - 1);
 472                          break;
 473                 default:        /* is it possible? */
 474                          error = EINVAL;
 475                          goto bad;
 476                 }
 477         }
 478
 479         /* Source address validation */
 480         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 481             (flags & IPV6_UNSPECSRC) == 0) {
 482                 error = EOPNOTSUPP;
 483                 ip6stat.ip6s_badscope++;
 484                 goto bad;
 485         }
 486         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 487                 error = EOPNOTSUPP;
 488                 ip6stat.ip6s_badscope++;
 489                 goto bad;
 490         }
 491
 492         ip6stat.ip6s_localout++;
 493
 494         /*
 495          * Route packet.
 496          */
 497         if (ro == 0) {
 498                 ro = &ip6route;
 499                 bzero((caddr_t)ro, sizeof(*ro));
 500         }
 501         ro_pmtu = ro;
 502         if (opt && opt->ip6po_rthdr)
 503                 ro = &opt->ip6po_route;
 504         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 505
 506 again:
 507         /*
 508          * if specified, try to fill in the traffic class field.
 509          * do not override if a non-zero value is already set.
 510          * we check the diffserv field and the ecn field separately.
 511          */
 512         if (opt && opt->ip6po_tclass >= 0) {
 513                 int mask = 0;
 514
 515                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 516                         mask |= 0xfc;
 517                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 518                         mask |= 0x03;
 519                 if (mask != 0)
 520                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 521         }
 522
 523         /* fill in or override the hop limit field, if necessary. */
 524         if (opt && opt->ip6po_hlim != -1)
 525                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 526         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 527                 if (im6o != NULL)
 528                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 529                 else
 530                         ip6->ip6_hlim = ip6_defmcasthlim;
 531         }
 532
 533 #ifdef IPSEC
 534         /*
 535          * We may re-inject packets into the stack here.
 536          */
 537         if (needipsec && needipsectun) {
 538                 struct ipsec_output_state state;
 539
 540                 /*
 541                  * All the extension headers will become inaccessible
 542                  * (since they can be encrypted).
 543                  * Don't panic, we need no more updates to extension headers
 544                  * on inner IPv6 packet (since they are now encapsulated).
 545                  *
 546                  * IPv6 [ESP|AH] IPv6 [extension headers] payload
 547                  */
 548                 bzero(&exthdrs, sizeof(exthdrs));
 549                 exthdrs.ip6e_ip6 = m;
 550
 551                 bzero(&state, sizeof(state));
 552                 state.m = m;
 553                 state.ro = (struct route *)ro;
 554                 state.dst = (struct sockaddr *)dst;
 555
 556                 error = ipsec6_output_tunnel(&state, sp, flags);
 557
 558                 m = state.m;
 559                 ro = (struct route_in6 *)state.ro;
 560                 dst = (struct sockaddr_in6 *)state.dst;
 561                 if (error == EJUSTRETURN) {
 562                         /*
 563                          * We had a SP with a level of 'use' and no SA. We
 564                          * will just continue to process the packet without
 565                          * IPsec processing.
 566                          */
 567                         ;
 568                 } else if (error) {
 569                         /* mbuf is already reclaimed in ipsec6_output_tunnel. */
 570                         m0 = m = NULL;
 571                         m = NULL;
 572                         switch (error) {
 573                         case EHOSTUNREACH:
 574                         case ENETUNREACH:
 575                         case EMSGSIZE:
 576                         case ENOBUFS:
 577                         case ENOMEM:
 578                                 break;
 579                         default:
 580                                 printf("[%s:%d] (ipsec): error code %d\n",
 581                                     __func__, __LINE__, error);
 582                                 /* FALLTHROUGH */
 583                         case ENOENT:
 584                                 /* don't show these error codes to the user */
 585                                 error = 0;
 586                                 break;
 587                         }
 588                         goto bad;
 589                 } else {
 590                         /*
 591                          * In the FAST IPSec case we have already
 592                          * re-injected the packet and it has been freed
 593                          * by the ipsec_done() function.  So, just clean
 594                          * up after ourselves.
 595                          */
 596                         m = NULL;
 597                         goto done;
 598                 }
 599
 600                 exthdrs.ip6e_ip6 = m;
 601         }
 602 #endif /* IPSEC */
 603
 604         /* adjust pointer */
 605         ip6 = mtod(m, struct ip6_hdr *);
 606
 607         bzero(&dst_sa, sizeof(dst_sa));
 608         dst_sa.sin6_family = AF_INET6;
 609         dst_sa.sin6_len = sizeof(dst_sa);
 610         dst_sa.sin6_addr = ip6->ip6_dst;
 611         if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
 612             &ifp, &rt, 0)) != 0) {
 613                 switch (error) {
 614                 case EHOSTUNREACH:
 615                         ip6stat.ip6s_noroute++;
 616                         break;
 617                 case EADDRNOTAVAIL:
 618                 default:
 619                         break; /* XXX statistics? */
 620                 }
 621                 if (ifp != NULL)
 622                         in6_ifstat_inc(ifp, ifs6_out_discard);
 623                 goto bad;
 624         }
 625         if (rt == NULL) {
 626                 /*
 627                  * If in6_selectroute() does not return a route entry,
 628                  * dst may not have been updated.
 629                  */
 630                 *dst = dst_sa;  /* XXX */
 631         }
 632
 633         /*
 634          * then rt (for unicast) and ifp must be non-NULL valid values.
 635          */
 636         if ((flags & IPV6_FORWARDING) == 0) {
 637                 /* XXX: the FORWARDING flag can be set for mrouting. */
 638                 in6_ifstat_inc(ifp, ifs6_out_request);
 639         }
 640         if (rt != NULL) {
 641                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 642                 rt->rt_use++;
 643         }
 644
 645         /*
 646          * The outgoing interface must be in the zone of source and
 647          * destination addresses.  We should use ia_ifp to support the
 648          * case of sending packets to an address of our own.
 649          */
 650         if (ia != NULL && ia->ia_ifp)
 651                 origifp = ia->ia_ifp;
 652         else
 653                 origifp = ifp;
 654
 655         src0 = ip6->ip6_src;
 656         if (in6_setscope(&src0, origifp, &zone))
 657                 goto badscope;
 658         bzero(&src_sa, sizeof(src_sa));
 659         src_sa.sin6_family = AF_INET6;
 660         src_sa.sin6_len = sizeof(src_sa);
 661         src_sa.sin6_addr = ip6->ip6_src;
 662         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 663                 goto badscope;
 664
 665         dst0 = ip6->ip6_dst;
 666         if (in6_setscope(&dst0, origifp, &zone))
 667                 goto badscope;
 668         /* re-initialize to be sure */
 669         bzero(&dst_sa, sizeof(dst_sa));
 670         dst_sa.sin6_family = AF_INET6;
 671         dst_sa.sin6_len = sizeof(dst_sa);
 672         dst_sa.sin6_addr = ip6->ip6_dst;
 673         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 674                 goto badscope;
 675         }
 676
 677         /* scope check is done. */
 678         goto routefound;
 679
 680   badscope:
 681         ip6stat.ip6s_badscope++;
 682         in6_ifstat_inc(origifp, ifs6_out_discard);
 683         if (error == 0)
 684                 error = EHOSTUNREACH; /* XXX */
 685         goto bad;
 686
 687   routefound:
 688         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 689                 if (opt && opt->ip6po_nextroute.ro_rt) {
 690                         /*
 691                          * The nexthop is explicitly specified by the
 692                          * application.  We assume the next hop is an IPv6
 693                          * address.
 694                          */
 695                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 696                 }
 697                 else if ((rt->rt_flags & RTF_GATEWAY))
 698                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 699         }
 700
 701         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 702                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 703         } else {
 704                 struct  in6_multi *in6m;
 705
 706                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 707
 708                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 709
 710                 /*
 711                  * Confirm that the outgoing interface supports multicast.
 712                  */
 713                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 714                         ip6stat.ip6s_noroute++;
 715                         in6_ifstat_inc(ifp, ifs6_out_discard);
 716                         error = ENETUNREACH;
 717                         goto bad;
 718                 }
 719                 IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
 720                 if (in6m != NULL &&
 721                    (im6o == NULL || im6o->im6o_multicast_loop)) {
 722                         /*
 723                          * If we belong to the destination multicast group
 724                          * on the outgoing interface, and the caller did not
 725                          * forbid loopback, loop back a copy.
 726                          */
 727                         ip6_mloopback(ifp, m, dst);
 728                 } else {
 729                         /*
 730                          * If we are acting as a multicast router, perform
 731                          * multicast forwarding as if the packet had just
 732                          * arrived on the interface to which we are about
 733                          * to send.  The multicast forwarding function
 734                          * recursively calls this function, using the
 735                          * IPV6_FORWARDING flag to prevent infinite recursion.
 736                          *
 737                          * Multicasts that are looped back by ip6_mloopback(),
 738                          * above, will be forwarded by the ip6_input() routine,
 739                          * if necessary.
 740                          */
 741                         if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 742                                 /*
 743                                  * XXX: ip6_mforward expects that rcvif is NULL
 744                                  * when it is called from the originating path.
 745                                  * However, it is not always the case, since
 746                                  * some versions of MGETHDR() does not
 747                                  * initialize the field.
 748                                  */
 749                                 m->m_pkthdr.rcvif = NULL;
 750                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 751                                         m_freem(m);
 752                                         goto done;
 753                                 }
 754                         }
 755                 }
 756                 /*
 757                  * Multicasts with a hoplimit of zero may be looped back,
 758                  * above, but must not be transmitted on a network.
 759                  * Also, multicasts addressed to the loopback interface
 760                  * are not sent -- the above call to ip6_mloopback() will
 761                  * loop back a copy if this host actually belongs to the
 762                  * destination group on the loopback interface.
 763                  */
 764                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 765                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 766                         m_freem(m);
 767                         goto done;
 768                 }
 769         }
 770
 771         /*
 772          * Fill the outgoing inteface to tell the upper layer
 773          * to increment per-interface statistics.
 774          */
 775         if (ifpp)
 776                 *ifpp = ifp;
 777
 778         /* Determine path MTU. */
 779         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
 780             &alwaysfrag)) != 0)
 781                 goto bad;
 782
 783         /*
 784          * The caller of this function may specify to use the minimum MTU
 785          * in some cases.
 786          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 787          * setting.  The logic is a bit complicated; by default, unicast
 788          * packets will follow path MTU while multicast packets will be sent at
 789          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 790          * including unicast ones will be sent at the minimum MTU.  Multicast
 791          * packets will always be sent at the minimum MTU unless
 792          * IP6PO_MINMTU_DISABLE is explicitly specified.
 793          * See RFC 3542 for more details.
 794          */
 795         if (mtu > IPV6_MMTU) {
 796                 if ((flags & IPV6_MINMTU))
 797                         mtu = IPV6_MMTU;
 798                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 799                         mtu = IPV6_MMTU;
 800                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 801                          (opt == NULL ||
 802                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 803                         mtu = IPV6_MMTU;
 804                 }
 805         }
 806
 807         /*
 808          * clear embedded scope identifiers if necessary.
 809          * in6_clearscope will touch the addresses only when necessary.
 810          */
 811         in6_clearscope(&ip6->ip6_src);
 812         in6_clearscope(&ip6->ip6_dst);
 813
 814         /*
 815          * If the outgoing packet contains a hop-by-hop options header,
 816          * it must be examined and processed even by the source node.
 817          * (RFC 2460, section 4.)
 818          */
 819         if (exthdrs.ip6e_hbh) {
 820                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 821                 u_int32_t dummy; /* XXX unused */
 822                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 823
 824 #ifdef DIAGNOSTIC
 825                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 826                         panic("ip6e_hbh is not continuous");
 827 #endif
 828                 /*
 829                  *  XXX: if we have to send an ICMPv6 error to the sender,
 830                  *       we need the M_LOOP flag since icmp6_error() expects
 831                  *       the IPv6 and the hop-by-hop options header are
 832                  *       continuous unless the flag is set.
 833                  */
 834                 m->m_flags |= M_LOOP;
 835                 m->m_pkthdr.rcvif = ifp;
 836                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 837                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 838                     &dummy, &plen) < 0) {
 839                         /* m was already freed at this point */
 840                         error = EINVAL;/* better error? */
 841                         goto done;
 842                 }
 843                 m->m_flags &= ~M_LOOP; /* XXX */
 844                 m->m_pkthdr.rcvif = NULL;
 845         }
 846
 847         /* Jump over all PFIL processing if hooks are not active. */
 848         if (!PFIL_HOOKED(&inet6_pfil_hook))
 849                 goto passout;
 850
 851         odst = ip6->ip6_dst;
 852         /* Run through list of hooks for output packets. */
 853         error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 854         if (error != 0 || m == NULL)
 855                 goto done;
 856         ip6 = mtod(m, struct ip6_hdr *);
 857
 858         /* See if destination IP address was changed by packet filter. */
 859         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 860                 m->m_flags |= M_SKIP_FIREWALL;
 861                 /* If destination is now ourself drop to ip6_input(). */
 862                 if (in6_localaddr(&ip6->ip6_dst)) {
 863                         if (m->m_pkthdr.rcvif == NULL)
 864                                 m->m_pkthdr.rcvif = loif;
 865                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 866                                 m->m_pkthdr.csum_flags |=
 867                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 868                                 m->m_pkthdr.csum_data = 0xffff;
 869                         }
 870                         m->m_pkthdr.csum_flags |=
 871                             CSUM_IP_CHECKED | CSUM_IP_VALID;
 872                         error = netisr_queue(NETISR_IPV6, m);
 873                         goto done;
 874                 } else
 875                         goto again;     /* Redo the routing table lookup. */
 876         }
 877
 878         /* XXX: IPFIREWALL_FORWARD */
 879
 880 passout:
 881         /*
 882          * Send the packet to the outgoing interface.
 883          * If necessary, do IPv6 fragmentation before sending.
 884          *
 885          * the logic here is rather complex:
 886          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 887          * 1-a: send as is if tlen <= path mtu
 888          * 1-b: fragment if tlen > path mtu
 889          *
 890          * 2: if user asks us not to fragment (dontfrag == 1)
 891          * 2-a: send as is if tlen <= interface mtu
 892          * 2-b: error if tlen > interface mtu
 893          *
 894          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 895          *      always fragment
 896          *
 897          * 4: if dontfrag == 1 && alwaysfrag == 1
 898          *      error, as we cannot handle this conflicting request
 899          */
 900         tlen = m->m_pkthdr.len;
 901
 902         if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
 903                 dontfrag = 1;
 904         else
 905                 dontfrag = 0;
 906         if (dontfrag && alwaysfrag) {   /* case 4 */
 907                 /* conflicting request - can't transmit */
 908                 error = EMSGSIZE;
 909                 goto bad;
 910         }
 911         if (dontfrag && tlen > IN6_LINKMTU(ifp)) {      /* case 2-b */
 912                 /*
 913                  * Even if the DONTFRAG option is specified, we cannot send the
 914                  * packet when the data length is larger than the MTU of the
 915                  * outgoing interface.
 916                  * Notify the error by sending IPV6_PATHMTU ancillary data as
 917                  * well as returning an error code (the latter is not described
 918                  * in the API spec.)
 919                  */
 920                 u_int32_t mtu32;
 921                 struct ip6ctlparam ip6cp;
 922
 923                 mtu32 = (u_int32_t)mtu;
 924                 bzero(&ip6cp, sizeof(ip6cp));
 925                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
 926                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
 927                     (void *)&ip6cp);
 928
 929                 error = EMSGSIZE;
 930                 goto bad;
 931         }
 932
 933         /*
 934          * transmit packet without fragmentation
 935          */
 936         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 937                 struct in6_ifaddr *ia6;
 938
 939                 ip6 = mtod(m, struct ip6_hdr *);
 940                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 941                 if (ia6) {
 942                         /* Record statistics for this interface address. */
 943                         ia6->ia_ifa.if_opackets++;
 944                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
 945                 }
 946                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
 947                 goto done;
 948         }
 949
 950         /*
 951          * try to fragment the packet.  case 1-b and 3
 952          */
 953         if (mtu < IPV6_MMTU) {
 954                 /* path MTU cannot be less than IPV6_MMTU */
 955                 error = EMSGSIZE;
 956                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 957                 goto bad;
 958         } else if (ip6->ip6_plen == 0) {
 959                 /* jumbo payload cannot be fragmented */
 960                 error = EMSGSIZE;
 961                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 962                 goto bad;
 963         } else {
 964                 struct mbuf **mnext, *m_frgpart;
 965                 struct ip6_frag *ip6f;
 966                 u_int32_t id = htonl(ip6_randomid());
 967                 u_char nextproto;
 968
 969                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
 970
 971                 /*
 972                  * Too large for the destination or interface;
 973                  * fragment if possible.
 974                  * Must be able to put at least 8 bytes per fragment.
 975                  */
 976                 hlen = unfragpartlen;
 977                 if (mtu > IPV6_MAXPACKET)
 978                         mtu = IPV6_MAXPACKET;
 979
 980                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 981                 if (len < 8) {
 982                         error = EMSGSIZE;
 983                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
 984                         goto bad;
 985                 }
 986
 987                 /*
 988                  * Verify that we have any chance at all of being able to queue
 989                  *      the packet or packet fragments
 990                  */
 991                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
 992                     < tlen  /* - hlen */)) {
 993                         error = ENOBUFS;
 994                         ip6stat.ip6s_odropped++;
 995                         goto bad;
 996                 }
 997
 998                 mnext = &m->m_nextpkt;
 999
1000                 /*
1001                  * Change the next header field of the last header in the
1002                  * unfragmentable part.
1003                  */
1004                 if (exthdrs.ip6e_rthdr) {
1005                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1006                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1007                 } else if (exthdrs.ip6e_dest1) {
1008                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1009                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1010                 } else if (exthdrs.ip6e_hbh) {
1011                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1012                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1013                 } else {
1014                         nextproto = ip6->ip6_nxt;
1015                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
1016                 }
1017
1018                 /*
1019                  * Loop through length of segment after first fragment,
1020                  * make new header and copy data of each part and link onto
1021                  * chain.
1022                  */
1023                 m0 = m;
1024                 for (off = hlen; off < tlen; off += len) {
1025                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
1026                         if (!m) {
1027                                 error = ENOBUFS;
1028                                 ip6stat.ip6s_odropped++;
1029                                 goto sendorfree;
1030                         }
1031                         m->m_pkthdr.rcvif = NULL;
1032                         m->m_flags = m0->m_flags & M_COPYFLAGS;
1033                         *mnext = m;
1034                         mnext = &m->m_nextpkt;
1035                         m->m_data += max_linkhdr;
1036                         mhip6 = mtod(m, struct ip6_hdr *);
1037                         *mhip6 = *ip6;
1038                         m->m_len = sizeof(*mhip6);
1039                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1040                         if (error) {
1041                                 ip6stat.ip6s_odropped++;
1042                                 goto sendorfree;
1043                         }
1044                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1045                         if (off + len >= tlen)
1046                                 len = tlen - off;
1047                         else
1048                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1049                         mhip6->ip6_plen = htons((u_short)(len + hlen +
1050                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1051                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1052                                 error = ENOBUFS;
1053                                 ip6stat.ip6s_odropped++;
1054                                 goto sendorfree;
1055                         }
1056                         m_cat(m, m_frgpart);
1057                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1058                         m->m_pkthdr.rcvif = NULL;
1059                         ip6f->ip6f_reserved = 0;
1060                         ip6f->ip6f_ident = id;
1061                         ip6f->ip6f_nxt = nextproto;
1062                         ip6stat.ip6s_ofragments++;
1063                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1064                 }
1065
1066                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1067         }
1068
1069         /*
1070          * Remove leading garbages.
1071          */
1072 sendorfree:
1073         m = m0->m_nextpkt;
1074         m0->m_nextpkt = 0;
1075         m_freem(m0);
1076         for (m0 = m; m; m = m0) {
1077                 m0 = m->m_nextpkt;
1078                 m->m_nextpkt = 0;
1079                 if (error == 0) {
1080                         /* Record statistics for this interface address. */
1081                         if (ia) {
1082                                 ia->ia_ifa.if_opackets++;
1083                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1084                         }
1085                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1086                 } else
1087                         m_freem(m);
1088         }
1089
1090         if (error == 0)
1091                 ip6stat.ip6s_fragmented++;
1092
1093 done:
1094         if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
1095                 RTFREE(ro->ro_rt);
1096         } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
1097                 RTFREE(ro_pmtu->ro_rt);
1098         }
1099 #ifdef IPSEC
1100         if (sp != NULL)
1101                 KEY_FREESP(&sp);
1102 #endif
1103
1104         return (error);
1105
1106 freehdrs:
1107         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1108         m_freem(exthdrs.ip6e_dest1);
1109         m_freem(exthdrs.ip6e_rthdr);
1110         m_freem(exthdrs.ip6e_dest2);
1111         /* FALLTHROUGH */
1112 bad:
1113         if (m)
1114                 m_freem(m);
1115         goto done;
1116 }
1117
1118 static int
1119 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1120 {
1121         struct mbuf *m;
1122
1123         if (hlen > MCLBYTES)
1124                 return (ENOBUFS); /* XXX */
1125
1126         MGET(m, M_DONTWAIT, MT_DATA);
1127         if (!m)
1128                 return (ENOBUFS);
1129
1130         if (hlen > MLEN) {
1131                 MCLGET(m, M_DONTWAIT);
1132                 if ((m->m_flags & M_EXT) == 0) {
1133                         m_free(m);
1134                         return (ENOBUFS);
1135                 }
1136         }
1137         m->m_len = hlen;
1138         if (hdr)
1139                 bcopy(hdr, mtod(m, caddr_t), hlen);
1140
1141         *mp = m;
1142         return (0);
1143 }
1144
1145 /*
1146  * Insert jumbo payload option.
1147  */
1148 static int
1149 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1150 {
1151         struct mbuf *mopt;
1152         u_char *optbuf;
1153         u_int32_t v;
1154
1155 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1156
1157         /*
1158          * If there is no hop-by-hop options header, allocate new one.
1159          * If there is one but it doesn't have enough space to store the
1160          * jumbo payload option, allocate a cluster to store the whole options.
1161          * Otherwise, use it to store the options.
1162          */
1163         if (exthdrs->ip6e_hbh == 0) {
1164                 MGET(mopt, M_DONTWAIT, MT_DATA);
1165                 if (mopt == 0)
1166                         return (ENOBUFS);
1167                 mopt->m_len = JUMBOOPTLEN;
1168                 optbuf = mtod(mopt, u_char *);
1169                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1170                 exthdrs->ip6e_hbh = mopt;
1171         } else {
1172                 struct ip6_hbh *hbh;
1173
1174                 mopt = exthdrs->ip6e_hbh;
1175                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1176                         /*
1177                          * XXX assumption:
1178                          * - exthdrs->ip6e_hbh is not referenced from places
1179                          *   other than exthdrs.
1180                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1181                          */
1182                         int oldoptlen = mopt->m_len;
1183                         struct mbuf *n;
1184
1185                         /*
1186                          * XXX: give up if the whole (new) hbh header does
1187                          * not fit even in an mbuf cluster.
1188                          */
1189                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1190                                 return (ENOBUFS);
1191
1192                         /*
1193                          * As a consequence, we must always prepare a cluster
1194                          * at this point.
1195                          */
1196                         MGET(n, M_DONTWAIT, MT_DATA);
1197                         if (n) {
1198                                 MCLGET(n, M_DONTWAIT);
1199                                 if ((n->m_flags & M_EXT) == 0) {
1200                                         m_freem(n);
1201                                         n = NULL;
1202                                 }
1203                         }
1204                         if (!n)
1205                                 return (ENOBUFS);
1206                         n->m_len = oldoptlen + JUMBOOPTLEN;
1207                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1208                             oldoptlen);
1209                         optbuf = mtod(n, caddr_t) + oldoptlen;
1210                         m_freem(mopt);
1211                         mopt = exthdrs->ip6e_hbh = n;
1212                 } else {
1213                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1214                         mopt->m_len += JUMBOOPTLEN;
1215                 }
1216                 optbuf[0] = IP6OPT_PADN;
1217                 optbuf[1] = 1;
1218
1219                 /*
1220                  * Adjust the header length according to the pad and
1221                  * the jumbo payload option.
1222                  */
1223                 hbh = mtod(mopt, struct ip6_hbh *);
1224                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1225         }
1226
1227         /* fill in the option. */
1228         optbuf[2] = IP6OPT_JUMBO;
1229         optbuf[3] = 4;
1230         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1231         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1232
1233         /* finally, adjust the packet header length */
1234         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1235
1236         return (0);
1237 #undef JUMBOOPTLEN
1238 }
1239
1240 /*
1241  * Insert fragment header and copy unfragmentable header portions.
1242  */
1243 static int
1244 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1245     struct ip6_frag **frghdrp)
1246 {
1247         struct mbuf *n, *mlast;
1248
1249         if (hlen > sizeof(struct ip6_hdr)) {
1250                 n = m_copym(m0, sizeof(struct ip6_hdr),
1251                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
1252                 if (n == 0)
1253                         return (ENOBUFS);
1254                 m->m_next = n;
1255         } else
1256                 n = m;
1257
1258         /* Search for the last mbuf of unfragmentable part. */
1259         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1260                 ;
1261
1262         if ((mlast->m_flags & M_EXT) == 0 &&
1263             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1264                 /* use the trailing space of the last mbuf for the fragment hdr */
1265                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1266                     mlast->m_len);
1267                 mlast->m_len += sizeof(struct ip6_frag);
1268                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1269         } else {
1270                 /* allocate a new mbuf for the fragment header */
1271                 struct mbuf *mfrg;
1272
1273                 MGET(mfrg, M_DONTWAIT, MT_DATA);
1274                 if (mfrg == 0)
1275                         return (ENOBUFS);
1276                 mfrg->m_len = sizeof(struct ip6_frag);
1277                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1278                 mlast->m_next = mfrg;
1279         }
1280
1281         return (0);
1282 }
1283
1284 static int
1285 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1286     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1287     int *alwaysfragp)
1288 {
1289         u_int32_t mtu = 0;
1290         int alwaysfrag = 0;
1291         int error = 0;
1292
1293         if (ro_pmtu != ro) {
1294                 /* The first hop and the final destination may differ. */
1295                 struct sockaddr_in6 *sa6_dst =
1296                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1297                 if (ro_pmtu->ro_rt &&
1298                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1299                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1300                         RTFREE(ro_pmtu->ro_rt);
1301                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
1302                 }
1303                 if (ro_pmtu->ro_rt == NULL) {
1304                         bzero(sa6_dst, sizeof(*sa6_dst));
1305                         sa6_dst->sin6_family = AF_INET6;
1306                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1307                         sa6_dst->sin6_addr = *dst;
1308
1309                         rtalloc((struct route *)ro_pmtu);
1310                 }
1311         }
1312         if (ro_pmtu->ro_rt) {
1313                 u_int32_t ifmtu;
1314                 struct in_conninfo inc;
1315
1316                 bzero(&inc, sizeof(inc));
1317                 inc.inc_flags |= INC_ISIPV6;
1318                 inc.inc6_faddr = *dst;
1319
1320                 if (ifp == NULL)
1321                         ifp = ro_pmtu->ro_rt->rt_ifp;
1322                 ifmtu = IN6_LINKMTU(ifp);
1323                 mtu = tcp_hc_getmtu(&inc);
1324                 if (mtu)
1325                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
1326                 else
1327                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1328                 if (mtu == 0)
1329                         mtu = ifmtu;
1330                 else if (mtu < IPV6_MMTU) {
1331                         /*
1332                          * RFC2460 section 5, last paragraph:
1333                          * if we record ICMPv6 too big message with
1334                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1335                          * or smaller, with framgent header attached.
1336                          * (fragment header is needed regardless from the
1337                          * packet size, for translators to identify packets)
1338                          */
1339                         alwaysfrag = 1;
1340                         mtu = IPV6_MMTU;
1341                 } else if (mtu > ifmtu) {
1342                         /*
1343                          * The MTU on the route is larger than the MTU on
1344                          * the interface!  This shouldn't happen, unless the
1345                          * MTU of the interface has been changed after the
1346                          * interface was brought up.  Change the MTU in the
1347                          * route to match the interface MTU (as long as the
1348                          * field isn't locked).
1349                          */
1350                         mtu = ifmtu;
1351                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1352                 }
1353         } else if (ifp) {
1354                 mtu = IN6_LINKMTU(ifp);
1355         } else
1356                 error = EHOSTUNREACH; /* XXX */
1357
1358         *mtup = mtu;
1359         if (alwaysfragp)
1360                 *alwaysfragp = alwaysfrag;
1361         return (error);
1362 }
1363
1364 /*
1365  * IP6 socket option processing.
1366  */
1367 int
1368 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1369 {
1370         int optdatalen, uproto;
1371         void *optdata;
1372         struct inpcb *in6p = sotoinpcb(so);
1373         int error, optval;
1374         int level, op, optname;
1375         int optlen;
1376         struct thread *td;
1377
1378         level = sopt->sopt_level;
1379         op = sopt->sopt_dir;
1380         optname = sopt->sopt_name;
1381         optlen = sopt->sopt_valsize;
1382         td = sopt->sopt_td;
1383         error = 0;
1384         optval = 0;
1385         uproto = (int)so->so_proto->pr_protocol;
1386
1387         if (level == IPPROTO_IPV6) {
1388                 switch (op) {
1389
1390                 case SOPT_SET:
1391                         switch (optname) {
1392                         case IPV6_2292PKTOPTIONS:
1393 #ifdef IPV6_PKTOPTIONS
1394                         case IPV6_PKTOPTIONS:
1395 #endif
1396                         {
1397                                 struct mbuf *m;
1398
1399                                 error = soopt_getm(sopt, &m); /* XXX */
1400                                 if (error != 0)
1401                                         break;
1402                                 error = soopt_mcopyin(sopt, m); /* XXX */
1403                                 if (error != 0)
1404                                         break;
1405                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1406                                                     m, so, sopt);
1407                                 m_freem(m); /* XXX */
1408                                 break;
1409                         }
1410
1411                         /*
1412                          * Use of some Hop-by-Hop options or some
1413                          * Destination options, might require special
1414                          * privilege.  That is, normal applications
1415                          * (without special privilege) might be forbidden
1416                          * from setting certain options in outgoing packets,
1417                          * and might never see certain options in received
1418                          * packets. [RFC 2292 Section 6]
1419                          * KAME specific note:
1420                          *  KAME prevents non-privileged users from sending or
1421                          *  receiving ANY hbh/dst options in order to avoid
1422                          *  overhead of parsing options in the kernel.
1423                          */
1424                         case IPV6_RECVHOPOPTS:
1425                         case IPV6_RECVDSTOPTS:
1426                         case IPV6_RECVRTHDRDSTOPTS:
1427                                 if (td != NULL) {
1428                                         error = priv_check(td,
1429                                             PRIV_NETINET_SETHDROPTS);
1430                                         if (error)
1431                                                 break;
1432                                 }
1433                                 /* FALLTHROUGH */
1434                         case IPV6_UNICAST_HOPS:
1435                         case IPV6_HOPLIMIT:
1436                         case IPV6_FAITH:
1437
1438                         case IPV6_RECVPKTINFO:
1439                         case IPV6_RECVHOPLIMIT:
1440                         case IPV6_RECVRTHDR:
1441                         case IPV6_RECVPATHMTU:
1442                         case IPV6_RECVTCLASS:
1443                         case IPV6_V6ONLY:
1444                         case IPV6_AUTOFLOWLABEL:
1445                                 if (optlen != sizeof(int)) {
1446                                         error = EINVAL;
1447                                         break;
1448                                 }
1449                                 error = sooptcopyin(sopt, &optval,
1450                                         sizeof optval, sizeof optval);
1451                                 if (error)
1452                                         break;
1453                                 switch (optname) {
1454
1455                                 case IPV6_UNICAST_HOPS:
1456                                         if (optval < -1 || optval >= 256)
1457                                                 error = EINVAL;
1458                                         else {
1459                                                 /* -1 = kernel default */
1460                                                 in6p->in6p_hops = optval;
1461                                                 if ((in6p->inp_vflag &
1462                                                      INP_IPV4) != 0)
1463                                                         in6p->inp_ip_ttl = optval;
1464                                         }
1465                                         break;
1466 #define OPTSET(bit) \
1467 do { \
1468         if (optval) \
1469                 in6p->inp_flags |= (bit); \
1470         else \
1471                 in6p->inp_flags &= ~(bit); \
1472 } while (/*CONSTCOND*/ 0)
1473 #define OPTSET2292(bit) \
1474 do { \
1475         in6p->inp_flags |= IN6P_RFC2292; \
1476         if (optval) \
1477                 in6p->inp_flags |= (bit); \
1478         else \
1479                 in6p->inp_flags &= ~(bit); \
1480 } while (/*CONSTCOND*/ 0)
1481 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1482
1483                                 case IPV6_RECVPKTINFO:
1484                                         /* cannot mix with RFC2292 */
1485                                         if (OPTBIT(IN6P_RFC2292)) {
1486                                                 error = EINVAL;
1487                                                 break;
1488                                         }
1489                                         OPTSET(IN6P_PKTINFO);
1490                                         break;
1491
1492                                 case IPV6_HOPLIMIT:
1493                                 {
1494                                         struct ip6_pktopts **optp;
1495
1496                                         /* cannot mix with RFC2292 */
1497                                         if (OPTBIT(IN6P_RFC2292)) {
1498                                                 error = EINVAL;
1499                                                 break;
1500                                         }
1501                                         optp = &in6p->in6p_outputopts;
1502                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1503                                             (u_char *)&optval, sizeof(optval),
1504                                             optp, (td != NULL) ? td->td_ucred :
1505                                             NULL, uproto);
1506                                         break;
1507                                 }
1508
1509                                 case IPV6_RECVHOPLIMIT:
1510                                         /* cannot mix with RFC2292 */
1511                                         if (OPTBIT(IN6P_RFC2292)) {
1512                                                 error = EINVAL;
1513                                                 break;
1514                                         }
1515                                         OPTSET(IN6P_HOPLIMIT);
1516                                         break;
1517
1518                                 case IPV6_RECVHOPOPTS:
1519                                         /* cannot mix with RFC2292 */
1520                                         if (OPTBIT(IN6P_RFC2292)) {
1521                                                 error = EINVAL;
1522                                                 break;
1523                                         }
1524                                         OPTSET(IN6P_HOPOPTS);
1525                                         break;
1526
1527                                 case IPV6_RECVDSTOPTS:
1528                                         /* cannot mix with RFC2292 */
1529                                         if (OPTBIT(IN6P_RFC2292)) {
1530                                                 error = EINVAL;
1531                                                 break;
1532                                         }
1533                                         OPTSET(IN6P_DSTOPTS);
1534                                         break;
1535
1536                                 case IPV6_RECVRTHDRDSTOPTS:
1537                                         /* cannot mix with RFC2292 */
1538                                         if (OPTBIT(IN6P_RFC2292)) {
1539                                                 error = EINVAL;
1540                                                 break;
1541                                         }
1542                                         OPTSET(IN6P_RTHDRDSTOPTS);
1543                                         break;
1544
1545                                 case IPV6_RECVRTHDR:
1546                                         /* cannot mix with RFC2292 */
1547                                         if (OPTBIT(IN6P_RFC2292)) {
1548                                                 error = EINVAL;
1549                                                 break;
1550                                         }
1551                                         OPTSET(IN6P_RTHDR);
1552                                         break;
1553
1554                                 case IPV6_FAITH:
1555                                         OPTSET(INP_FAITH);
1556                                         break;
1557
1558                                 case IPV6_RECVPATHMTU:
1559                                         /*
1560                                          * We ignore this option for TCP
1561                                          * sockets.
1562                                          * (RFC3542 leaves this case
1563                                          * unspecified.)
1564                                          */
1565                                         if (uproto != IPPROTO_TCP)
1566                                                 OPTSET(IN6P_MTU);
1567                                         break;
1568
1569                                 case IPV6_V6ONLY:
1570                                         /*
1571                                          * make setsockopt(IPV6_V6ONLY)
1572                                          * available only prior to bind(2).
1573                                          * see ipng mailing list, Jun 22 2001.
1574                                          */
1575                                         if (in6p->inp_lport ||
1576                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1577                                                 error = EINVAL;
1578                                                 break;
1579                                         }
1580                                         OPTSET(IN6P_IPV6_V6ONLY);
1581                                         if (optval)
1582                                                 in6p->inp_vflag &= ~INP_IPV4;
1583                                         else
1584                                                 in6p->inp_vflag |= INP_IPV4;
1585                                         break;
1586                                 case IPV6_RECVTCLASS:
1587                                         /* cannot mix with RFC2292 XXX */
1588                                         if (OPTBIT(IN6P_RFC2292)) {
1589                                                 error = EINVAL;
1590                                                 break;
1591                                         }
1592                                         OPTSET(IN6P_TCLASS);
1593                                         break;
1594                                 case IPV6_AUTOFLOWLABEL:
1595                                         OPTSET(IN6P_AUTOFLOWLABEL);
1596                                         break;
1597
1598                                 }
1599                                 break;
1600
1601                         case IPV6_TCLASS:
1602                         case IPV6_DONTFRAG:
1603                         case IPV6_USE_MIN_MTU:
1604                         case IPV6_PREFER_TEMPADDR:
1605                                 if (optlen != sizeof(optval)) {
1606                                         error = EINVAL;
1607                                         break;
1608                                 }
1609                                 error = sooptcopyin(sopt, &optval,
1610                                         sizeof optval, sizeof optval);
1611                                 if (error)
1612                                         break;
1613                                 {
1614                                         struct ip6_pktopts **optp;
1615                                         optp = &in6p->in6p_outputopts;
1616                                         error = ip6_pcbopt(optname,
1617                                             (u_char *)&optval, sizeof(optval),
1618                                             optp, (td != NULL) ? td->td_ucred :
1619                                             NULL, uproto);
1620                                         break;
1621                                 }
1622
1623                         case IPV6_2292PKTINFO:
1624                         case IPV6_2292HOPLIMIT:
1625                         case IPV6_2292HOPOPTS:
1626                         case IPV6_2292DSTOPTS:
1627                         case IPV6_2292RTHDR:
1628                                 /* RFC 2292 */
1629                                 if (optlen != sizeof(int)) {
1630                                         error = EINVAL;
1631                                         break;
1632                                 }
1633                                 error = sooptcopyin(sopt, &optval,
1634                                         sizeof optval, sizeof optval);
1635                                 if (error)
1636                                         break;
1637                                 switch (optname) {
1638                                 case IPV6_2292PKTINFO:
1639                                         OPTSET2292(IN6P_PKTINFO);
1640                                         break;
1641                                 case IPV6_2292HOPLIMIT:
1642                                         OPTSET2292(IN6P_HOPLIMIT);
1643                                         break;
1644                                 case IPV6_2292HOPOPTS:
1645                                         /*
1646                                          * Check super-user privilege.
1647                                          * See comments for IPV6_RECVHOPOPTS.
1648                                          */
1649                                         if (td != NULL) {
1650                                                 error = priv_check(td,
1651                                                     PRIV_NETINET_SETHDROPTS);
1652                                                 if (error)
1653                                                         return (error);
1654                                         }
1655                                         OPTSET2292(IN6P_HOPOPTS);
1656                                         break;
1657                                 case IPV6_2292DSTOPTS:
1658                                         if (td != NULL) {
1659                                                 error = priv_check(td,
1660                                                     PRIV_NETINET_SETHDROPTS);
1661                                                 if (error)
1662                                                         return (error);
1663                                         }
1664                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1665                                         break;
1666                                 case IPV6_2292RTHDR:
1667                                         OPTSET2292(IN6P_RTHDR);
1668                                         break;
1669                                 }
1670                                 break;
1671                         case IPV6_PKTINFO:
1672                         case IPV6_HOPOPTS:
1673                         case IPV6_RTHDR:
1674                         case IPV6_DSTOPTS:
1675                         case IPV6_RTHDRDSTOPTS:
1676                         case IPV6_NEXTHOP:
1677                         {
1678                                 /* new advanced API (RFC3542) */
1679                                 u_char *optbuf;
1680                                 u_char optbuf_storage[MCLBYTES];
1681                                 int optlen;
1682                                 struct ip6_pktopts **optp;
1683
1684                                 /* cannot mix with RFC2292 */
1685                                 if (OPTBIT(IN6P_RFC2292)) {
1686                                         error = EINVAL;
1687                                         break;
1688                                 }
1689
1690                                 /*
1691                                  * We only ensure valsize is not too large
1692                                  * here.  Further validation will be done
1693                                  * later.
1694                                  */
1695                                 error = sooptcopyin(sopt, optbuf_storage,
1696                                     sizeof(optbuf_storage), 0);
1697                                 if (error)
1698                                         break;
1699                                 optlen = sopt->sopt_valsize;
1700                                 optbuf = optbuf_storage;
1701                                 optp = &in6p->in6p_outputopts;
1702                                 error = ip6_pcbopt(optname, optbuf, optlen,
1703                                     optp, (td != NULL) ? td->td_ucred : NULL,
1704                                     uproto);
1705                                 break;
1706                         }
1707 #undef OPTSET
1708
1709                         case IPV6_MULTICAST_IF:
1710                         case IPV6_MULTICAST_HOPS:
1711                         case IPV6_MULTICAST_LOOP:
1712                         case IPV6_JOIN_GROUP:
1713                         case IPV6_LEAVE_GROUP:
1714                             {
1715                                 if (sopt->sopt_valsize > MLEN) {
1716                                         error = EMSGSIZE;
1717                                         break;
1718                                 }
1719                                 /* XXX */
1720                             }
1721                             /* FALLTHROUGH */
1722                             {
1723                                 struct mbuf *m;
1724
1725                                 if (sopt->sopt_valsize > MCLBYTES) {
1726                                         error = EMSGSIZE;
1727                                         break;
1728                                 }
1729                                 /* XXX */
1730                                 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
1731                                 if (m == 0) {
1732                                         error = ENOBUFS;
1733                                         break;
1734                                 }
1735                                 if (sopt->sopt_valsize > MLEN) {
1736                                         MCLGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT);
1737                                         if ((m->m_flags & M_EXT) == 0) {
1738                                                 m_free(m);
1739                                                 error = ENOBUFS;
1740                                                 break;
1741                                         }
1742                                 }
1743                                 m->m_len = sopt->sopt_valsize;
1744                                 error = sooptcopyin(sopt, mtod(m, char *),
1745                                                     m->m_len, m->m_len);
1746                                 if (error) {
1747                                         (void)m_free(m);
1748                                         break;
1749                                 }
1750                                 error = ip6_setmoptions(sopt->sopt_name,
1751                                                         &in6p->in6p_moptions,
1752                                                         m);
1753                                 (void)m_free(m);
1754                             }
1755                                 break;
1756
1757                         case IPV6_PORTRANGE:
1758                                 error = sooptcopyin(sopt, &optval,
1759                                     sizeof optval, sizeof optval);
1760                                 if (error)
1761                                         break;
1762
1763                                 switch (optval) {
1764                                 case IPV6_PORTRANGE_DEFAULT:
1765                                         in6p->inp_flags &= ~(INP_LOWPORT);
1766                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1767                                         break;
1768
1769                                 case IPV6_PORTRANGE_HIGH:
1770                                         in6p->inp_flags &= ~(INP_LOWPORT);
1771                                         in6p->inp_flags |= INP_HIGHPORT;
1772                                         break;
1773
1774                                 case IPV6_PORTRANGE_LOW:
1775                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1776                                         in6p->inp_flags |= INP_LOWPORT;
1777                                         break;
1778
1779                                 default:
1780                                         error = EINVAL;
1781                                         break;
1782                                 }
1783                                 break;
1784
1785 #ifdef IPSEC
1786                         case IPV6_IPSEC_POLICY:
1787                         {
1788                                 caddr_t req;
1789                                 struct mbuf *m;
1790
1791                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1792                                         break;
1793                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1794                                         break;
1795                                 req = mtod(m, caddr_t);
1796                                 error = ipsec6_set_policy(in6p, optname, req,
1797                                     m->m_len, (sopt->sopt_td != NULL) ?
1798                                     sopt->sopt_td->td_ucred : NULL);
1799                                 m_freem(m);
1800                                 break;
1801                         }
1802 #endif /* IPSEC */
1803
1804                         default:
1805                                 error = ENOPROTOOPT;
1806                                 break;
1807                         }
1808                         break;
1809
1810                 case SOPT_GET:
1811                         switch (optname) {
1812
1813                         case IPV6_2292PKTOPTIONS:
1814 #ifdef IPV6_PKTOPTIONS
1815                         case IPV6_PKTOPTIONS:
1816 #endif
1817                                 /*
1818                                  * RFC3542 (effectively) deprecated the
1819                                  * semantics of the 2292-style pktoptions.
1820                                  * Since it was not reliable in nature (i.e.,
1821                                  * applications had to expect the lack of some
1822                                  * information after all), it would make sense
1823                                  * to simplify this part by always returning
1824                                  * empty data.
1825                                  */
1826                                 sopt->sopt_valsize = 0;
1827                                 break;
1828
1829                         case IPV6_RECVHOPOPTS:
1830                         case IPV6_RECVDSTOPTS:
1831                         case IPV6_RECVRTHDRDSTOPTS:
1832                         case IPV6_UNICAST_HOPS:
1833                         case IPV6_RECVPKTINFO:
1834                         case IPV6_RECVHOPLIMIT:
1835                         case IPV6_RECVRTHDR:
1836                         case IPV6_RECVPATHMTU:
1837
1838                         case IPV6_FAITH:
1839                         case IPV6_V6ONLY:
1840                         case IPV6_PORTRANGE:
1841                         case IPV6_RECVTCLASS:
1842                         case IPV6_AUTOFLOWLABEL:
1843                                 switch (optname) {
1844
1845                                 case IPV6_RECVHOPOPTS:
1846                                         optval = OPTBIT(IN6P_HOPOPTS);
1847                                         break;
1848
1849                                 case IPV6_RECVDSTOPTS:
1850                                         optval = OPTBIT(IN6P_DSTOPTS);
1851                                         break;
1852
1853                                 case IPV6_RECVRTHDRDSTOPTS:
1854                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1855                                         break;
1856
1857                                 case IPV6_UNICAST_HOPS:
1858                                         optval = in6p->in6p_hops;
1859                                         break;
1860
1861                                 case IPV6_RECVPKTINFO:
1862                                         optval = OPTBIT(IN6P_PKTINFO);
1863                                         break;
1864
1865                                 case IPV6_RECVHOPLIMIT:
1866                                         optval = OPTBIT(IN6P_HOPLIMIT);
1867                                         break;
1868
1869                                 case IPV6_RECVRTHDR:
1870                                         optval = OPTBIT(IN6P_RTHDR);
1871                                         break;
1872
1873                                 case IPV6_RECVPATHMTU:
1874                                         optval = OPTBIT(IN6P_MTU);
1875                                         break;
1876
1877                                 case IPV6_FAITH:
1878                                         optval = OPTBIT(INP_FAITH);
1879                                         break;
1880
1881                                 case IPV6_V6ONLY:
1882                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1883                                         break;
1884
1885                                 case IPV6_PORTRANGE:
1886                                     {
1887                                         int flags;
1888                                         flags = in6p->inp_flags;
1889                                         if (flags & INP_HIGHPORT)
1890                                                 optval = IPV6_PORTRANGE_HIGH;
1891                                         else if (flags & INP_LOWPORT)
1892                                                 optval = IPV6_PORTRANGE_LOW;
1893                                         else
1894                                                 optval = 0;
1895                                         break;
1896                                     }
1897                                 case IPV6_RECVTCLASS:
1898                                         optval = OPTBIT(IN6P_TCLASS);
1899                                         break;
1900
1901                                 case IPV6_AUTOFLOWLABEL:
1902                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1903                                         break;
1904                                 }
1905                                 if (error)
1906                                         break;
1907                                 error = sooptcopyout(sopt, &optval,
1908                                         sizeof optval);
1909                                 break;
1910
1911                         case IPV6_PATHMTU:
1912                         {
1913                                 u_long pmtu = 0;
1914                                 struct ip6_mtuinfo mtuinfo;
1915                                 struct route_in6 sro;
1916
1917                                 bzero(&sro, sizeof(sro));
1918
1919                                 if (!(so->so_state & SS_ISCONNECTED))
1920                                         return (ENOTCONN);
1921                                 /*
1922                                  * XXX: we dot not consider the case of source
1923                                  * routing, or optional information to specify
1924                                  * the outgoing interface.
1925                                  */
1926                                 error = ip6_getpmtu(&sro, NULL, NULL,
1927                                     &in6p->in6p_faddr, &pmtu, NULL);
1928                                 if (sro.ro_rt)
1929                                         RTFREE(sro.ro_rt);
1930                                 if (error)
1931                                         break;
1932                                 if (pmtu > IPV6_MAXPACKET)
1933                                         pmtu = IPV6_MAXPACKET;
1934
1935                                 bzero(&mtuinfo, sizeof(mtuinfo));
1936                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1937                                 optdata = (void *)&mtuinfo;
1938                                 optdatalen = sizeof(mtuinfo);
1939                                 error = sooptcopyout(sopt, optdata,
1940                                     optdatalen);
1941                                 break;
1942                         }
1943
1944                         case IPV6_2292PKTINFO:
1945                         case IPV6_2292HOPLIMIT:
1946                         case IPV6_2292HOPOPTS:
1947                         case IPV6_2292RTHDR:
1948                         case IPV6_2292DSTOPTS:
1949                                 switch (optname) {
1950                                 case IPV6_2292PKTINFO:
1951                                         optval = OPTBIT(IN6P_PKTINFO);
1952                                         break;
1953                                 case IPV6_2292HOPLIMIT:
1954                                         optval = OPTBIT(IN6P_HOPLIMIT);
1955                                         break;
1956                                 case IPV6_2292HOPOPTS:
1957                                         optval = OPTBIT(IN6P_HOPOPTS);
1958                                         break;
1959                                 case IPV6_2292RTHDR:
1960                                         optval = OPTBIT(IN6P_RTHDR);
1961                                         break;
1962                                 case IPV6_2292DSTOPTS:
1963                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1964                                         break;
1965                                 }
1966                                 error = sooptcopyout(sopt, &optval,
1967                                     sizeof optval);
1968                                 break;
1969                         case IPV6_PKTINFO:
1970                         case IPV6_HOPOPTS:
1971                         case IPV6_RTHDR:
1972                         case IPV6_DSTOPTS:
1973                         case IPV6_RTHDRDSTOPTS:
1974                         case IPV6_NEXTHOP:
1975                         case IPV6_TCLASS:
1976                         case IPV6_DONTFRAG:
1977                         case IPV6_USE_MIN_MTU:
1978                         case IPV6_PREFER_TEMPADDR:
1979                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
1980                                     optname, sopt);
1981                                 break;
1982
1983                         case IPV6_MULTICAST_IF:
1984                         case IPV6_MULTICAST_HOPS:
1985                         case IPV6_MULTICAST_LOOP:
1986                         case IPV6_JOIN_GROUP:
1987                         case IPV6_LEAVE_GROUP:
1988                             {
1989                                 struct mbuf *m;
1990                                 error = ip6_getmoptions(sopt->sopt_name,
1991                                     in6p->in6p_moptions, &m);
1992                                 if (error == 0)
1993                                         error = sooptcopyout(sopt,
1994                                             mtod(m, char *), m->m_len);
1995                                 m_freem(m);
1996                             }
1997                                 break;
1998
1999 #ifdef IPSEC
2000                         case IPV6_IPSEC_POLICY:
2001                           {
2002                                 caddr_t req = NULL;
2003                                 size_t len = 0;
2004                                 struct mbuf *m = NULL;
2005                                 struct mbuf **mp = &m;
2006                                 size_t ovalsize = sopt->sopt_valsize;
2007                                 caddr_t oval = (caddr_t)sopt->sopt_val;
2008
2009                                 error = soopt_getm(sopt, &m); /* XXX */
2010                                 if (error != 0)
2011                                         break;
2012                                 error = soopt_mcopyin(sopt, m); /* XXX */
2013                                 if (error != 0)
2014                                         break;
2015                                 sopt->sopt_valsize = ovalsize;
2016                                 sopt->sopt_val = oval;
2017                                 if (m) {
2018                                         req = mtod(m, caddr_t);
2019                                         len = m->m_len;
2020                                 }
2021                                 error = ipsec6_get_policy(in6p, req, len, mp);
2022                                 if (error == 0)
2023                                         error = soopt_mcopyout(sopt, m); /* XXX */
2024                                 if (error == 0 && m)
2025                                         m_freem(m);
2026                                 break;
2027                           }
2028 #endif /* IPSEC */
2029
2030                         default:
2031                                 error = ENOPROTOOPT;
2032                                 break;
2033                         }
2034                         break;
2035                 }
2036         } else {                /* level != IPPROTO_IPV6 */
2037                 error = EINVAL;
2038         }
2039         return (error);
2040 }
2041
2042 int
2043 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2044 {
2045         int error = 0, optval, optlen;
2046         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2047         struct inpcb *in6p = sotoinpcb(so);
2048         int level, op, optname;
2049
2050         level = sopt->sopt_level;
2051         op = sopt->sopt_dir;
2052         optname = sopt->sopt_name;
2053         optlen = sopt->sopt_valsize;
2054
2055         if (level != IPPROTO_IPV6) {
2056                 return (EINVAL);
2057         }
2058
2059         switch (optname) {
2060         case IPV6_CHECKSUM:
2061                 /*
2062                  * For ICMPv6 sockets, no modification allowed for checksum
2063                  * offset, permit "no change" values to help existing apps.
2064                  *
2065                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2066                  * for an ICMPv6 socket will fail."
2067                  * The current behavior does not meet RFC3542.
2068                  */
2069                 switch (op) {
2070                 case SOPT_SET:
2071                         if (optlen != sizeof(int)) {
2072                                 error = EINVAL;
2073                                 break;
2074                         }
2075                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2076                                             sizeof(optval));
2077                         if (error)
2078                                 break;
2079                         if ((optval % 2) != 0) {
2080                                 /* the API assumes even offset values */
2081                                 error = EINVAL;
2082                         } else if (so->so_proto->pr_protocol ==
2083                             IPPROTO_ICMPV6) {
2084                                 if (optval != icmp6off)
2085                                         error = EINVAL;
2086                         } else
2087                                 in6p->in6p_cksum = optval;
2088                         break;
2089
2090                 case SOPT_GET:
2091                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2092                                 optval = icmp6off;
2093                         else
2094                                 optval = in6p->in6p_cksum;
2095
2096                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2097                         break;
2098
2099                 default:
2100                         error = EINVAL;
2101                         break;
2102                 }
2103                 break;
2104
2105         default:
2106                 error = ENOPROTOOPT;
2107                 break;
2108         }
2109
2110         return (error);
2111 }
2112
2113 /*
2114  * Set up IP6 options in pcb for insertion in output packets or
2115  * specifying behavior of outgoing packets.
2116  */
2117 static int
2118 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2119     struct socket *so, struct sockopt *sopt)
2120 {
2121         struct ip6_pktopts *opt = *pktopt;
2122         int error = 0;
2123         struct thread *td = sopt->sopt_td;
2124
2125         /* turn off any old options. */
2126         if (opt) {
2127 #ifdef DIAGNOSTIC
2128                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2129                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2130                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2131                         printf("ip6_pcbopts: all specified options are cleared.\n");
2132 #endif
2133                 ip6_clearpktopts(opt, -1);
2134         } else
2135                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2136         *pktopt = NULL;
2137
2138         if (!m || m->m_len == 0) {
2139                 /*
2140                  * Only turning off any previous options, regardless of
2141                  * whether the opt is just created or given.
2142                  */
2143                 free(opt, M_IP6OPT);
2144                 return (0);
2145         }
2146
2147         /*  set options specified by user. */
2148         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2149             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2150                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2151                 free(opt, M_IP6OPT);
2152                 return (error);
2153         }
2154         *pktopt = opt;
2155         return (0);
2156 }
2157
2158 /*
2159  * initialize ip6_pktopts.  beware that there are non-zero default values in
2160  * the struct.
2161  */
2162 void
2163 ip6_initpktopts(struct ip6_pktopts *opt)
2164 {
2165
2166         bzero(opt, sizeof(*opt));
2167         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2168         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2169         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2170         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2171 }
2172
2173 static int
2174 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2175     struct ucred *cred, int uproto)
2176 {
2177         struct ip6_pktopts *opt;
2178
2179         if (*pktopt == NULL) {
2180                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2181                     M_WAITOK);
2182                 ip6_initpktopts(*pktopt);
2183         }
2184         opt = *pktopt;
2185
2186         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2187 }
2188
2189 static int
2190 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2191 {
2192         void *optdata = NULL;
2193         int optdatalen = 0;
2194         struct ip6_ext *ip6e;
2195         int error = 0;
2196         struct in6_pktinfo null_pktinfo;
2197         int deftclass = 0, on;
2198         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2199         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2200
2201         switch (optname) {
2202         case IPV6_PKTINFO:
2203                 if (pktopt && pktopt->ip6po_pktinfo)
2204                         optdata = (void *)pktopt->ip6po_pktinfo;
2205                 else {
2206                         /* XXX: we don't have to do this every time... */
2207                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2208                         optdata = (void *)&null_pktinfo;
2209                 }
2210                 optdatalen = sizeof(struct in6_pktinfo);
2211                 break;
2212         case IPV6_TCLASS:
2213                 if (pktopt && pktopt->ip6po_tclass >= 0)
2214                         optdata = (void *)&pktopt->ip6po_tclass;
2215                 else
2216                         optdata = (void *)&deftclass;
2217                 optdatalen = sizeof(int);
2218                 break;
2219         case IPV6_HOPOPTS:
2220                 if (pktopt && pktopt->ip6po_hbh) {
2221                         optdata = (void *)pktopt->ip6po_hbh;
2222                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2223                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2224                 }
2225                 break;
2226         case IPV6_RTHDR:
2227                 if (pktopt && pktopt->ip6po_rthdr) {
2228                         optdata = (void *)pktopt->ip6po_rthdr;
2229                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2230                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2231                 }
2232                 break;
2233         case IPV6_RTHDRDSTOPTS:
2234                 if (pktopt && pktopt->ip6po_dest1) {
2235                         optdata = (void *)pktopt->ip6po_dest1;
2236                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2237                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2238                 }
2239                 break;
2240         case IPV6_DSTOPTS:
2241                 if (pktopt && pktopt->ip6po_dest2) {
2242                         optdata = (void *)pktopt->ip6po_dest2;
2243                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2244                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2245                 }
2246                 break;
2247         case IPV6_NEXTHOP:
2248                 if (pktopt && pktopt->ip6po_nexthop) {
2249                         optdata = (void *)pktopt->ip6po_nexthop;
2250                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2251                 }
2252                 break;
2253         case IPV6_USE_MIN_MTU:
2254                 if (pktopt)
2255                         optdata = (void *)&pktopt->ip6po_minmtu;
2256                 else
2257                         optdata = (void *)&defminmtu;
2258                 optdatalen = sizeof(int);
2259                 break;
2260         case IPV6_DONTFRAG:
2261                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2262                         on = 1;
2263                 else
2264                         on = 0;
2265                 optdata = (void *)&on;
2266                 optdatalen = sizeof(on);
2267                 break;
2268         case IPV6_PREFER_TEMPADDR:
2269                 if (pktopt)
2270                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2271                 else
2272                         optdata = (void *)&defpreftemp;
2273                 optdatalen = sizeof(int);
2274                 break;
2275         default:                /* should not happen */
2276 #ifdef DIAGNOSTIC
2277                 panic("ip6_getpcbopt: unexpected option\n");
2278 #endif
2279                 return (ENOPROTOOPT);
2280         }
2281
2282         error = sooptcopyout(sopt, optdata, optdatalen);
2283
2284         return (error);
2285 }
2286
2287 void
2288 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2289 {
2290         if (pktopt == NULL)
2291                 return;
2292
2293         if (optname == -1 || optname == IPV6_PKTINFO) {
2294                 if (pktopt->ip6po_pktinfo)
2295                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2296                 pktopt->ip6po_pktinfo = NULL;
2297         }
2298         if (optname == -1 || optname == IPV6_HOPLIMIT)
2299                 pktopt->ip6po_hlim = -1;
2300         if (optname == -1 || optname == IPV6_TCLASS)
2301                 pktopt->ip6po_tclass = -1;
2302         if (optname == -1 || optname == IPV6_NEXTHOP) {
2303                 if (pktopt->ip6po_nextroute.ro_rt) {
2304                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2305                         pktopt->ip6po_nextroute.ro_rt = NULL;
2306                 }
2307                 if (pktopt->ip6po_nexthop)
2308                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2309                 pktopt->ip6po_nexthop = NULL;
2310         }
2311         if (optname == -1 || optname == IPV6_HOPOPTS) {
2312                 if (pktopt->ip6po_hbh)
2313                         free(pktopt->ip6po_hbh, M_IP6OPT);
2314                 pktopt->ip6po_hbh = NULL;
2315         }
2316         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2317                 if (pktopt->ip6po_dest1)
2318                         free(pktopt->ip6po_dest1, M_IP6OPT);
2319                 pktopt->ip6po_dest1 = NULL;
2320         }
2321         if (optname == -1 || optname == IPV6_RTHDR) {
2322                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2323                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2324                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2325                 if (pktopt->ip6po_route.ro_rt) {
2326                         RTFREE(pktopt->ip6po_route.ro_rt);
2327                         pktopt->ip6po_route.ro_rt = NULL;
2328                 }
2329         }
2330         if (optname == -1 || optname == IPV6_DSTOPTS) {
2331                 if (pktopt->ip6po_dest2)
2332                         free(pktopt->ip6po_dest2, M_IP6OPT);
2333                 pktopt->ip6po_dest2 = NULL;
2334         }
2335 }
2336
2337 #define PKTOPT_EXTHDRCPY(type) \
2338 do {\
2339         if (src->type) {\
2340                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2341                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2342                 if (dst->type == NULL && canwait == M_NOWAIT)\
2343                         goto bad;\
2344                 bcopy(src->type, dst->type, hlen);\
2345         }\
2346 } while (/*CONSTCOND*/ 0)
2347
2348 static int
2349 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2350 {
2351         if (dst == NULL || src == NULL)  {
2352                 printf("ip6_clearpktopts: invalid argument\n");
2353                 return (EINVAL);
2354         }
2355
2356         dst->ip6po_hlim = src->ip6po_hlim;
2357         dst->ip6po_tclass = src->ip6po_tclass;
2358         dst->ip6po_flags = src->ip6po_flags;
2359         if (src->ip6po_pktinfo) {
2360                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2361                     M_IP6OPT, canwait);
2362                 if (dst->ip6po_pktinfo == NULL)
2363                         goto bad;
2364                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2365         }
2366         if (src->ip6po_nexthop) {
2367                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2368                     M_IP6OPT, canwait);
2369                 if (dst->ip6po_nexthop == NULL)
2370                         goto bad;
2371                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2372                     src->ip6po_nexthop->sa_len);
2373         }
2374         PKTOPT_EXTHDRCPY(ip6po_hbh);
2375         PKTOPT_EXTHDRCPY(ip6po_dest1);
2376         PKTOPT_EXTHDRCPY(ip6po_dest2);
2377         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2378         return (0);
2379
2380   bad:
2381         ip6_clearpktopts(dst, -1);
2382         return (ENOBUFS);
2383 }
2384 #undef PKTOPT_EXTHDRCPY
2385
2386 struct ip6_pktopts *
2387 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2388 {
2389         int error;
2390         struct ip6_pktopts *dst;
2391
2392         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2393         if (dst == NULL)
2394                 return (NULL);
2395         ip6_initpktopts(dst);
2396
2397         if ((error = copypktopts(dst, src, canwait)) != 0) {
2398                 free(dst, M_IP6OPT);
2399                 return (NULL);
2400         }
2401
2402         return (dst);
2403 }
2404
2405 void
2406 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2407 {
2408         if (pktopt == NULL)
2409                 return;
2410
2411         ip6_clearpktopts(pktopt, -1);
2412
2413         free(pktopt, M_IP6OPT);
2414 }
2415
2416 /*
2417  * Set the IP6 multicast options in response to user setsockopt().
2418  */
2419 static int
2420 ip6_setmoptions(int optname, struct ip6_moptions **im6op, struct mbuf *m)
2421 {
2422         int error = 0;
2423         u_int loop, ifindex;
2424         struct ipv6_mreq *mreq;
2425         struct ifnet *ifp;
2426         struct ip6_moptions *im6o = *im6op;
2427         struct route_in6 ro;
2428         struct in6_multi_mship *imm;
2429
2430         if (im6o == NULL) {
2431                 /*
2432                  * No multicast option buffer attached to the pcb;
2433                  * allocate one and initialize to default values.
2434                  */
2435                 im6o = (struct ip6_moptions *)
2436                         malloc(sizeof(*im6o), M_IP6MOPTS, M_WAITOK);
2437
2438                 if (im6o == NULL)
2439                         return (ENOBUFS);
2440                 *im6op = im6o;
2441                 im6o->im6o_multicast_ifp = NULL;
2442                 im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2443                 im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
2444                 LIST_INIT(&im6o->im6o_memberships);
2445         }
2446
2447         switch (optname) {
2448
2449         case IPV6_MULTICAST_IF:
2450                 /*
2451                  * Select the interface for outgoing multicast packets.
2452                  */
2453                 if (m == NULL || m->m_len != sizeof(u_int)) {
2454                         error = EINVAL;
2455                         break;
2456                 }
2457                 bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
2458                 if (ifindex < 0 || if_index < ifindex) {
2459                         error = ENXIO;  /* XXX EINVAL? */
2460                         break;
2461                 }
2462                 ifp = ifnet_byindex(ifindex);
2463                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
2464                         error = EADDRNOTAVAIL;
2465                         break;
2466                 }
2467                 im6o->im6o_multicast_ifp = ifp;
2468                 break;
2469
2470         case IPV6_MULTICAST_HOPS:
2471             {
2472                 /*
2473                  * Set the IP6 hoplimit for outgoing multicast packets.
2474                  */
2475                 int optval;
2476                 if (m == NULL || m->m_len != sizeof(int)) {
2477                         error = EINVAL;
2478                         break;
2479                 }
2480                 bcopy(mtod(m, u_int *), &optval, sizeof(optval));
2481                 if (optval < -1 || optval >= 256)
2482                         error = EINVAL;
2483                 else if (optval == -1)
2484                         im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2485                 else
2486                         im6o->im6o_multicast_hlim = optval;
2487                 break;
2488             }
2489
2490         case IPV6_MULTICAST_LOOP:
2491                 /*
2492                  * Set the loopback flag for outgoing multicast packets.
2493                  * Must be zero or one.
2494                  */
2495                 if (m == NULL || m->m_len != sizeof(u_int)) {
2496                         error = EINVAL;
2497                         break;
2498                 }
2499                 bcopy(mtod(m, u_int *), &loop, sizeof(loop));
2500                 if (loop > 1) {
2501                         error = EINVAL;
2502                         break;
2503                 }
2504                 im6o->im6o_multicast_loop = loop;
2505                 break;
2506
2507         case IPV6_JOIN_GROUP:
2508                 /*
2509                  * Add a multicast group membership.
2510                  * Group must be a valid IP6 multicast address.
2511                  */
2512                 if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2513                         error = EINVAL;
2514                         break;
2515                 }
2516                 mreq = mtod(m, struct ipv6_mreq *);
2517
2518                 if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2519                         /*
2520                          * We use the unspecified address to specify to accept
2521                          * all multicast addresses. Only super user is allowed
2522                          * to do this.
2523                          */
2524                         /* XXX-BZ might need a better PRIV_NETINET_x for this */
2525                         error = priv_check(curthread, PRIV_NETINET_MROUTE);
2526                         if (error)
2527                                 break;
2528                 } else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2529                         error = EINVAL;
2530                         break;
2531                 }
2532
2533                 /*
2534                  * If no interface was explicitly specified, choose an
2535                  * appropriate one according to the given multicast address.
2536                  */
2537                 if (mreq->ipv6mr_interface == 0) {
2538                         struct sockaddr_in6 *dst;
2539
2540                         /*
2541                          * Look up the routing table for the
2542                          * address, and choose the outgoing interface.
2543                          *   XXX: is it a good approach?
2544                          */
2545                         ro.ro_rt = NULL;
2546                         dst = (struct sockaddr_in6 *)&ro.ro_dst;
2547                         bzero(dst, sizeof(*dst));
2548                         dst->sin6_family = AF_INET6;
2549                         dst->sin6_len = sizeof(*dst);
2550                         dst->sin6_addr = mreq->ipv6mr_multiaddr;
2551                         rtalloc((struct route *)&ro);
2552                         if (ro.ro_rt == NULL) {
2553                                 error = EADDRNOTAVAIL;
2554                                 break;
2555                         }
2556                         ifp = ro.ro_rt->rt_ifp;
2557                         RTFREE(ro.ro_rt);
2558                 } else {
2559                         /*
2560                          * If the interface is specified, validate it.
2561                          */
2562                         if (mreq->ipv6mr_interface < 0 ||
2563                             if_index < mreq->ipv6mr_interface) {
2564                                 error = ENXIO;  /* XXX EINVAL? */
2565                                 break;
2566                         }
2567                         ifp = ifnet_byindex(mreq->ipv6mr_interface);
2568                         if (!ifp) {
2569                                 error = ENXIO;  /* XXX EINVAL? */
2570                                 break;
2571                         }
2572                 }
2573
2574                 /*
2575                  * See if we found an interface, and confirm that it
2576                  * supports multicast
2577                  */
2578                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
2579                         error = EADDRNOTAVAIL;
2580                         break;
2581                 }
2582
2583                 if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
2584                         error = EADDRNOTAVAIL; /* XXX: should not happen */
2585                         break;
2586                 }
2587
2588                 /*
2589                  * See if the membership already exists.
2590                  */
2591                 for (imm = im6o->im6o_memberships.lh_first;
2592                      imm != NULL; imm = imm->i6mm_chain.le_next)
2593                         if (imm->i6mm_maddr->in6m_ifp == ifp &&
2594                             IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2595                                                &mreq->ipv6mr_multiaddr))
2596                                 break;
2597                 if (imm != NULL) {
2598                         error = EADDRINUSE;
2599                         break;
2600                 }
2601                 /*
2602                  * Everything looks good; add a new record to the multicast
2603                  * address list for the given interface.
2604                  */
2605                 imm = in6_joingroup(ifp, &mreq->ipv6mr_multiaddr,  &error, 0);
2606                 if (imm == NULL)
2607                         break;
2608                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
2609                 break;
2610
2611         case IPV6_LEAVE_GROUP:
2612                 /*
2613                  * Drop a multicast group membership.
2614                  * Group must be a valid IP6 multicast address.
2615                  */
2616                 if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2617                         error = EINVAL;
2618                         break;
2619                 }
2620                 mreq = mtod(m, struct ipv6_mreq *);
2621
2622                 /*
2623                  * If an interface address was specified, get a pointer
2624                  * to its ifnet structure.
2625                  */
2626                 if (mreq->ipv6mr_interface < 0 ||
2627                     if_index < mreq->ipv6mr_interface) {
2628                         error = ENXIO;  /* XXX EINVAL? */
2629                         break;
2630                 }
2631                 if (mreq->ipv6mr_interface == 0)
2632                         ifp = NULL;
2633                 else
2634                         ifp = ifnet_byindex(mreq->ipv6mr_interface);
2635
2636                 /* Fill in the scope zone ID */
2637                 if (ifp) {
2638                         if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
2639                                 /* XXX: should not happen */
2640                                 error = EADDRNOTAVAIL;
2641                                 break;
2642                         }
2643                 } else if (mreq->ipv6mr_interface != 0) {
2644                         /*
2645                          * This case happens when the (positive) index is in
2646                          * the valid range, but the corresponding interface has
2647                          * been detached dynamically (XXX).
2648                          */
2649                         error = EADDRNOTAVAIL;
2650                         break;
2651                 } else {        /* ipv6mr_interface == 0 */
2652                         struct sockaddr_in6 sa6_mc;
2653
2654                         /*
2655                          * The API spec says as follows:
2656                          *  If the interface index is specified as 0, the
2657                          *  system may choose a multicast group membership to
2658                          *  drop by matching the multicast address only.
2659                          * On the other hand, we cannot disambiguate the scope
2660                          * zone unless an interface is provided.  Thus, we
2661                          * check if there's ambiguity with the default scope
2662                          * zone as the last resort.
2663                          */
2664                         bzero(&sa6_mc, sizeof(sa6_mc));
2665                         sa6_mc.sin6_family = AF_INET6;
2666                         sa6_mc.sin6_len = sizeof(sa6_mc);
2667                         sa6_mc.sin6_addr = mreq->ipv6mr_multiaddr;
2668                         error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
2669                         if (error != 0)
2670                                 break;
2671                         mreq->ipv6mr_multiaddr = sa6_mc.sin6_addr;
2672                 }
2673
2674                 /*
2675                  * Find the membership in the membership list.
2676                  */
2677                 for (imm = im6o->im6o_memberships.lh_first;
2678                      imm != NULL; imm = imm->i6mm_chain.le_next) {
2679                         if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
2680                             IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2681                             &mreq->ipv6mr_multiaddr))
2682                                 break;
2683                 }
2684                 if (imm == NULL) {
2685                         /* Unable to resolve interface */
2686                         error = EADDRNOTAVAIL;
2687                         break;
2688                 }
2689                 /*
2690                  * Give up the multicast address record to which the
2691                  * membership points.
2692                  */
2693                 LIST_REMOVE(imm, i6mm_chain);
2694                 in6_delmulti(imm->i6mm_maddr);
2695                 free(imm, M_IP6MADDR);
2696                 break;
2697
2698         default:
2699                 error = EOPNOTSUPP;
2700                 break;
2701         }
2702
2703         /*
2704          * If all options have default values, no need to keep the mbuf.
2705          */
2706         if (im6o->im6o_multicast_ifp == NULL &&
2707             im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
2708             im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
2709             im6o->im6o_memberships.lh_first == NULL) {
2710                 free(*im6op, M_IP6MOPTS);
2711                 *im6op = NULL;
2712         }
2713
2714         return (error);
2715 }
2716
2717 /*
2718  * Return the IP6 multicast options in response to user getsockopt().
2719  */
2720 static int
2721 ip6_getmoptions(int optname, struct ip6_moptions *im6o, struct mbuf **mp)
2722 {
2723         u_int *hlim, *loop, *ifindex;
2724
2725         *mp = m_get(M_TRYWAIT, MT_HEADER);              /* XXX */
2726
2727         switch (optname) {
2728
2729         case IPV6_MULTICAST_IF:
2730                 ifindex = mtod(*mp, u_int *);
2731                 (*mp)->m_len = sizeof(u_int);
2732                 if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
2733                         *ifindex = 0;
2734                 else
2735                         *ifindex = im6o->im6o_multicast_ifp->if_index;
2736                 return (0);
2737
2738         case IPV6_MULTICAST_HOPS:
2739                 hlim = mtod(*mp, u_int *);
2740                 (*mp)->m_len = sizeof(u_int);
2741                 if (im6o == NULL)
2742                         *hlim = ip6_defmcasthlim;
2743                 else
2744                         *hlim = im6o->im6o_multicast_hlim;
2745                 return (0);
2746
2747         case IPV6_MULTICAST_LOOP:
2748                 loop = mtod(*mp, u_int *);
2749                 (*mp)->m_len = sizeof(u_int);
2750                 if (im6o == NULL)
2751                         *loop = ip6_defmcasthlim;
2752                 else
2753                         *loop = im6o->im6o_multicast_loop;
2754                 return (0);
2755
2756         default:
2757                 return (EOPNOTSUPP);
2758         }
2759 }
2760
2761 /*
2762  * Discard the IP6 multicast options.
2763  */
2764 void
2765 ip6_freemoptions(struct ip6_moptions *im6o)
2766 {
2767         struct in6_multi_mship *imm;
2768
2769         if (im6o == NULL)
2770                 return;
2771
2772         while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
2773                 LIST_REMOVE(imm, i6mm_chain);
2774                 if (imm->i6mm_maddr)
2775                         in6_delmulti(imm->i6mm_maddr);
2776                 free(imm, M_IP6MADDR);
2777         }
2778         free(im6o, M_IP6MOPTS);
2779 }
2780
2781 /*
2782  * Set IPv6 outgoing packet options based on advanced API.
2783  */
2784 int
2785 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2786     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2787 {
2788         struct cmsghdr *cm = 0;
2789
2790         if (control == NULL || opt == NULL)
2791                 return (EINVAL);
2792
2793         ip6_initpktopts(opt);
2794         if (stickyopt) {
2795                 int error;
2796
2797                 /*
2798                  * If stickyopt is provided, make a local copy of the options
2799                  * for this particular packet, then override them by ancillary
2800                  * objects.
2801                  * XXX: copypktopts() does not copy the cached route to a next
2802                  * hop (if any).  This is not very good in terms of efficiency,
2803                  * but we can allow this since this option should be rarely
2804                  * used.
2805                  */
2806                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2807                         return (error);
2808         }
2809
2810         /*
2811          * XXX: Currently, we assume all the optional information is stored
2812          * in a single mbuf.
2813          */
2814         if (control->m_next)
2815                 return (EINVAL);
2816
2817         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2818             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2819                 int error;
2820
2821                 if (control->m_len < CMSG_LEN(0))
2822                         return (EINVAL);
2823
2824                 cm = mtod(control, struct cmsghdr *);
2825                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2826                         return (EINVAL);
2827                 if (cm->cmsg_level != IPPROTO_IPV6)
2828                         continue;
2829
2830                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2831                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2832                 if (error)
2833                         return (error);
2834         }
2835
2836         return (0);
2837 }
2838
2839 /*
2840  * Set a particular packet option, as a sticky option or an ancillary data
2841  * item.  "len" can be 0 only when it's a sticky option.
2842  * We have 4 cases of combination of "sticky" and "cmsg":
2843  * "sticky=0, cmsg=0": impossible
2844  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2845  * "sticky=1, cmsg=0": RFC3542 socket option
2846  * "sticky=1, cmsg=1": RFC2292 socket option
2847  */
2848 static int
2849 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2850     struct ucred *cred, int sticky, int cmsg, int uproto)
2851 {
2852         int minmtupolicy, preftemp;
2853         int error;
2854
2855         if (!sticky && !cmsg) {
2856 #ifdef DIAGNOSTIC
2857                 printf("ip6_setpktopt: impossible case\n");
2858 #endif
2859                 return (EINVAL);
2860         }
2861
2862         /*
2863          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2864          * not be specified in the context of RFC3542.  Conversely,
2865          * RFC3542 types should not be specified in the context of RFC2292.
2866          */
2867         if (!cmsg) {
2868                 switch (optname) {
2869                 case IPV6_2292PKTINFO:
2870                 case IPV6_2292HOPLIMIT:
2871                 case IPV6_2292NEXTHOP:
2872                 case IPV6_2292HOPOPTS:
2873                 case IPV6_2292DSTOPTS:
2874                 case IPV6_2292RTHDR:
2875                 case IPV6_2292PKTOPTIONS:
2876                         return (ENOPROTOOPT);
2877                 }
2878         }
2879         if (sticky && cmsg) {
2880                 switch (optname) {
2881                 case IPV6_PKTINFO:
2882                 case IPV6_HOPLIMIT:
2883                 case IPV6_NEXTHOP:
2884                 case IPV6_HOPOPTS:
2885                 case IPV6_DSTOPTS:
2886                 case IPV6_RTHDRDSTOPTS:
2887                 case IPV6_RTHDR:
2888                 case IPV6_USE_MIN_MTU:
2889                 case IPV6_DONTFRAG:
2890                 case IPV6_TCLASS:
2891                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2892                         return (ENOPROTOOPT);
2893                 }
2894         }
2895
2896         switch (optname) {
2897         case IPV6_2292PKTINFO:
2898         case IPV6_PKTINFO:
2899         {
2900                 struct ifnet *ifp = NULL;
2901                 struct in6_pktinfo *pktinfo;
2902
2903                 if (len != sizeof(struct in6_pktinfo))
2904                         return (EINVAL);
2905
2906                 pktinfo = (struct in6_pktinfo *)buf;
2907
2908                 /*
2909                  * An application can clear any sticky IPV6_PKTINFO option by
2910                  * doing a "regular" setsockopt with ipi6_addr being
2911                  * in6addr_any and ipi6_ifindex being zero.
2912                  * [RFC 3542, Section 6]
2913                  */
2914                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2915                     pktinfo->ipi6_ifindex == 0 &&
2916                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2917                         ip6_clearpktopts(opt, optname);
2918                         break;
2919                 }
2920
2921                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2922                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2923                         return (EINVAL);
2924                 }
2925
2926                 /* validate the interface index if specified. */
2927                 if (pktinfo->ipi6_ifindex > if_index ||
2928                     pktinfo->ipi6_ifindex < 0) {
2929                          return (ENXIO);
2930                 }
2931                 if (pktinfo->ipi6_ifindex) {
2932                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2933                         if (ifp == NULL)
2934                                 return (ENXIO);
2935                 }
2936
2937                 /*
2938                  * We store the address anyway, and let in6_selectsrc()
2939                  * validate the specified address.  This is because ipi6_addr
2940                  * may not have enough information about its scope zone, and
2941                  * we may need additional information (such as outgoing
2942                  * interface or the scope zone of a destination address) to
2943                  * disambiguate the scope.
2944                  * XXX: the delay of the validation may confuse the
2945                  * application when it is used as a sticky option.
2946                  */
2947                 if (opt->ip6po_pktinfo == NULL) {
2948                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2949                             M_IP6OPT, M_NOWAIT);
2950                         if (opt->ip6po_pktinfo == NULL)
2951                                 return (ENOBUFS);
2952                 }
2953                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2954                 break;
2955         }
2956
2957         case IPV6_2292HOPLIMIT:
2958         case IPV6_HOPLIMIT:
2959         {
2960                 int *hlimp;
2961
2962                 /*
2963                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2964                  * to simplify the ordering among hoplimit options.
2965                  */
2966                 if (optname == IPV6_HOPLIMIT && sticky)
2967                         return (ENOPROTOOPT);
2968
2969                 if (len != sizeof(int))
2970                         return (EINVAL);
2971                 hlimp = (int *)buf;
2972                 if (*hlimp < -1 || *hlimp > 255)
2973                         return (EINVAL);
2974
2975                 opt->ip6po_hlim = *hlimp;
2976                 break;
2977         }
2978
2979         case IPV6_TCLASS:
2980         {
2981                 int tclass;
2982
2983                 if (len != sizeof(int))
2984                         return (EINVAL);
2985                 tclass = *(int *)buf;
2986                 if (tclass < -1 || tclass > 255)
2987                         return (EINVAL);
2988
2989                 opt->ip6po_tclass = tclass;
2990                 break;
2991         }
2992
2993         case IPV6_2292NEXTHOP:
2994         case IPV6_NEXTHOP:
2995                 if (cred != NULL) {
2996                         error = priv_check_cred(cred,
2997                             PRIV_NETINET_SETHDROPTS, 0);
2998                         if (error)
2999                                 return (error);
3000                 }
3001
3002                 if (len == 0) { /* just remove the option */
3003                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
3004                         break;
3005                 }
3006
3007                 /* check if cmsg_len is large enough for sa_len */
3008                 if (len < sizeof(struct sockaddr) || len < *buf)
3009                         return (EINVAL);
3010
3011                 switch (((struct sockaddr *)buf)->sa_family) {
3012                 case AF_INET6:
3013                 {
3014                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
3015                         int error;
3016
3017                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
3018                                 return (EINVAL);
3019
3020                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
3021                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
3022                                 return (EINVAL);
3023                         }
3024                         if ((error = sa6_embedscope(sa6, ip6_use_defzone))
3025                             != 0) {
3026                                 return (error);
3027                         }
3028                         break;
3029                 }
3030                 case AF_LINK:   /* should eventually be supported */
3031                 default:
3032                         return (EAFNOSUPPORT);
3033                 }
3034
3035                 /* turn off the previous option, then set the new option. */
3036                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
3037                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
3038                 if (opt->ip6po_nexthop == NULL)
3039                         return (ENOBUFS);
3040                 bcopy(buf, opt->ip6po_nexthop, *buf);
3041                 break;
3042
3043         case IPV6_2292HOPOPTS:
3044         case IPV6_HOPOPTS:
3045         {
3046                 struct ip6_hbh *hbh;
3047                 int hbhlen;
3048
3049                 /*
3050                  * XXX: We don't allow a non-privileged user to set ANY HbH
3051                  * options, since per-option restriction has too much
3052                  * overhead.
3053                  */
3054                 if (cred != NULL) {
3055                         error = priv_check_cred(cred,
3056                             PRIV_NETINET_SETHDROPTS, 0);
3057                         if (error)
3058                                 return (error);
3059                 }
3060
3061                 if (len == 0) {
3062                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
3063                         break;  /* just remove the option */
3064                 }
3065
3066                 /* message length validation */
3067                 if (len < sizeof(struct ip6_hbh))
3068                         return (EINVAL);
3069                 hbh = (struct ip6_hbh *)buf;
3070                 hbhlen = (hbh->ip6h_len + 1) << 3;
3071                 if (len != hbhlen)
3072                         return (EINVAL);
3073
3074                 /* turn off the previous option, then set the new option. */
3075                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
3076                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
3077                 if (opt->ip6po_hbh == NULL)
3078                         return (ENOBUFS);
3079                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
3080
3081                 break;
3082         }
3083
3084         case IPV6_2292DSTOPTS:
3085         case IPV6_DSTOPTS:
3086         case IPV6_RTHDRDSTOPTS:
3087         {
3088                 struct ip6_dest *dest, **newdest = NULL;
3089                 int destlen;
3090
3091                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
3092                         error = priv_check_cred(cred,
3093                             PRIV_NETINET_SETHDROPTS, 0);
3094                         if (error)
3095                                 return (error);
3096                 }
3097
3098                 if (len == 0) {
3099                         ip6_clearpktopts(opt, optname);
3100                         break;  /* just remove the option */
3101                 }
3102
3103                 /* message length validation */
3104                 if (len < sizeof(struct ip6_dest))
3105                         return (EINVAL);
3106                 dest = (struct ip6_dest *)buf;
3107                 destlen = (dest->ip6d_len + 1) << 3;
3108                 if (len != destlen)
3109                         return (EINVAL);
3110
3111                 /*
3112                  * Determine the position that the destination options header
3113                  * should be inserted; before or after the routing header.
3114                  */
3115                 switch (optname) {
3116                 case IPV6_2292DSTOPTS:
3117                         /*
3118                          * The old advacned API is ambiguous on this point.
3119                          * Our approach is to determine the position based
3120                          * according to the existence of a routing header.
3121                          * Note, however, that this depends on the order of the
3122                          * extension headers in the ancillary data; the 1st
3123                          * part of the destination options header must appear
3124                          * before the routing header in the ancillary data,
3125                          * too.
3126                          * RFC3542 solved the ambiguity by introducing
3127                          * separate ancillary data or option types.
3128                          */
3129                         if (opt->ip6po_rthdr == NULL)
3130                                 newdest = &opt->ip6po_dest1;
3131                         else
3132                                 newdest = &opt->ip6po_dest2;
3133                         break;
3134                 case IPV6_RTHDRDSTOPTS:
3135                         newdest = &opt->ip6po_dest1;
3136                         break;
3137                 case IPV6_DSTOPTS:
3138                         newdest = &opt->ip6po_dest2;
3139                         break;
3140                 }
3141
3142                 /* turn off the previous option, then set the new option. */
3143                 ip6_clearpktopts(opt, optname);
3144                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
3145                 if (*newdest == NULL)
3146                         return (ENOBUFS);
3147                 bcopy(dest, *newdest, destlen);
3148
3149                 break;
3150         }
3151
3152         case IPV6_2292RTHDR:
3153         case IPV6_RTHDR:
3154         {
3155                 struct ip6_rthdr *rth;
3156                 int rthlen;
3157
3158                 if (len == 0) {
3159                         ip6_clearpktopts(opt, IPV6_RTHDR);
3160                         break;  /* just remove the option */
3161                 }
3162
3163                 /* message length validation */
3164                 if (len < sizeof(struct ip6_rthdr))
3165                         return (EINVAL);
3166                 rth = (struct ip6_rthdr *)buf;
3167                 rthlen = (rth->ip6r_len + 1) << 3;
3168                 if (len != rthlen)
3169                         return (EINVAL);
3170
3171                 switch (rth->ip6r_type) {
3172                 case IPV6_RTHDR_TYPE_0:
3173                         if (rth->ip6r_len == 0) /* must contain one addr */
3174                                 return (EINVAL);
3175                         if (rth->ip6r_len % 2) /* length must be even */
3176                                 return (EINVAL);
3177                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
3178                                 return (EINVAL);
3179                         break;
3180                 default:
3181                         return (EINVAL);        /* not supported */
3182                 }
3183
3184                 /* turn off the previous option */
3185                 ip6_clearpktopts(opt, IPV6_RTHDR);
3186                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
3187                 if (opt->ip6po_rthdr == NULL)
3188                         return (ENOBUFS);
3189                 bcopy(rth, opt->ip6po_rthdr, rthlen);
3190
3191                 break;
3192         }
3193
3194         case IPV6_USE_MIN_MTU:
3195                 if (len != sizeof(int))
3196                         return (EINVAL);
3197                 minmtupolicy = *(int *)buf;
3198                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3199                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
3200                     minmtupolicy != IP6PO_MINMTU_ALL) {
3201                         return (EINVAL);
3202                 }
3203                 opt->ip6po_minmtu = minmtupolicy;
3204                 break;
3205
3206         case IPV6_DONTFRAG:
3207                 if (len != sizeof(int))
3208                         return (EINVAL);
3209
3210                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3211                         /*
3212                          * we ignore this option for TCP sockets.
3213                          * (RFC3542 leaves this case unspecified.)
3214                          */
3215                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3216                 } else
3217                         opt->ip6po_flags |= IP6PO_DONTFRAG;
3218                 break;
3219
3220         case IPV6_PREFER_TEMPADDR:
3221                 if (len != sizeof(int))
3222                         return (EINVAL);
3223                 preftemp = *(int *)buf;
3224                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3225                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3226                     preftemp != IP6PO_TEMPADDR_PREFER) {
3227                         return (EINVAL);
3228                 }
3229                 opt->ip6po_prefer_tempaddr = preftemp;
3230                 break;
3231
3232         default:
3233                 return (ENOPROTOOPT);
3234         } /* end of switch */
3235
3236         return (0);
3237 }
3238
3239 /*
3240  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3241  * packet to the input queue of a specified interface.  Note that this
3242  * calls the output routine of the loopback "driver", but with an interface
3243  * pointer that might NOT be &loif -- easier than replicating that code here.
3244  */
3245 void
3246 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
3247 {
3248         struct mbuf *copym;
3249         struct ip6_hdr *ip6;
3250
3251         copym = m_copy(m, 0, M_COPYALL);
3252         if (copym == NULL)
3253                 return;
3254
3255         /*
3256          * Make sure to deep-copy IPv6 header portion in case the data
3257          * is in an mbuf cluster, so that we can safely override the IPv6
3258          * header portion later.
3259          */
3260         if ((copym->m_flags & M_EXT) != 0 ||
3261             copym->m_len < sizeof(struct ip6_hdr)) {
3262                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3263                 if (copym == NULL)
3264                         return;
3265         }
3266
3267 #ifdef DIAGNOSTIC
3268         if (copym->m_len < sizeof(*ip6)) {
3269                 m_freem(copym);
3270                 return;
3271         }
3272 #endif
3273
3274         ip6 = mtod(copym, struct ip6_hdr *);
3275         /*
3276          * clear embedded scope identifiers if necessary.
3277          * in6_clearscope will touch the addresses only when necessary.
3278          */
3279         in6_clearscope(&ip6->ip6_src);
3280         in6_clearscope(&ip6->ip6_dst);
3281
3282         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
3283 }
3284
3285 /*
3286  * Chop IPv6 header off from the payload.
3287  */
3288 static int
3289 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3290 {
3291         struct mbuf *mh;
3292         struct ip6_hdr *ip6;
3293
3294         ip6 = mtod(m, struct ip6_hdr *);
3295         if (m->m_len > sizeof(*ip6)) {
3296                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
3297                 if (mh == 0) {
3298                         m_freem(m);
3299                         return ENOBUFS;
3300                 }
3301                 M_MOVE_PKTHDR(mh, m);
3302                 MH_ALIGN(mh, sizeof(*ip6));
3303                 m->m_len -= sizeof(*ip6);
3304                 m->m_data += sizeof(*ip6);
3305                 mh->m_next = m;
3306                 m = mh;
3307                 m->m_len = sizeof(*ip6);
3308                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3309         }
3310         exthdrs->ip6e_ip6 = m;
3311         return 0;
3312 }
3313
3314 /*
3315  * Compute IPv6 extension header length.
3316  */
3317 int
3318 ip6_optlen(struct inpcb *in6p)
3319 {
3320         int len;
3321
3322         if (!in6p->in6p_outputopts)
3323                 return 0;
3324
3325         len = 0;
3326 #define elen(x) \
3327     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3328
3329         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3330         if (in6p->in6p_outputopts->ip6po_rthdr)
3331                 /* dest1 is valid with rthdr only */
3332                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3333         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3334         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3335         return len;
3336 #undef elen
3337 }