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_ipfw.h"
  69 #include "opt_ipsec.h"
  70 #include "opt_sctp.h"
  71 #include "opt_route.h"
  72
  73 #include <sys/param.h>
  74 #include <sys/kernel.h>
  75 #include <sys/malloc.h>
  76 #include <sys/mbuf.h>
  77 #include <sys/errno.h>
  78 #include <sys/priv.h>
  79 #include <sys/proc.h>
  80 #include <sys/protosw.h>
  81 #include <sys/socket.h>
  82 #include <sys/socketvar.h>
  83 #include <sys/syslog.h>
  84 #include <sys/ucred.h>
  85
  86 #include <net/if.h>
  87 #include <net/netisr.h>
  88 #include <net/route.h>
  89 #include <net/pfil.h>
  90 #include <net/vnet.h>
  91
  92 #include <netinet/in.h>
  93 #include <netinet/in_var.h>
  94 #include <netinet/ip_var.h>
  95 #include <netinet6/in6_var.h>
  96 #include <netinet/ip6.h>
  97 #include <netinet/icmp6.h>
  98 #include <netinet6/ip6_var.h>
  99 #include <netinet/in_pcb.h>
 100 #include <netinet/tcp_var.h>
 101 #include <netinet6/nd6.h>
 102
 103 #ifdef IPSEC
 104 #include <netipsec/ipsec.h>
 105 #include <netipsec/ipsec6.h>
 106 #include <netipsec/key.h>
 107 #include <netinet6/ip6_ipsec.h>
 108 #endif /* IPSEC */
 109 #ifdef SCTP
 110 #include <netinet/sctp.h>
 111 #include <netinet/sctp_crc32.h>
 112 #endif
 113
 114 #include <netinet6/ip6protosw.h>
 115 #include <netinet6/scope6_var.h>
 116
 117 #ifdef FLOWTABLE
 118 #include <net/flowtable.h>
 119 #endif
 120
 121 extern int in6_mcast_loop;
 122
 123 struct ip6_exthdrs {
 124         struct mbuf *ip6e_ip6;
 125         struct mbuf *ip6e_hbh;
 126         struct mbuf *ip6e_dest1;
 127         struct mbuf *ip6e_rthdr;
 128         struct mbuf *ip6e_dest2;
 129 };
 130
 131 static int ip6_pcbopt __P((int, u_char *, int, struct ip6_pktopts **,
 132                            struct ucred *, int));
 133 static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
 134         struct socket *, struct sockopt *));
 135 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
 136 static int ip6_setpktopt __P((int, u_char *, int, struct ip6_pktopts *,
 137         struct ucred *, int, int, int));
 138
 139 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 140 static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
 141         struct ip6_frag **));
 142 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 143 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 144 static int ip6_getpmtu __P((struct route_in6 *, struct route_in6 *,
 145         struct ifnet *, struct in6_addr *, u_long *, int *));
 146 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 147
 148
 149 /*
 150  * Make an extension header from option data.  hp is the source, and
 151  * mp is the destination.
 152  */
 153 #define MAKE_EXTHDR(hp, mp)                                             \
 154     do {                                                                \
 155         if (hp) {                                                       \
 156                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 157                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 158                     ((eh)->ip6e_len + 1) << 3);                         \
 159                 if (error)                                              \
 160                         goto freehdrs;                                  \
 161         }                                                               \
 162     } while (/*CONSTCOND*/ 0)
 163
 164 /*
 165  * Form a chain of extension headers.
 166  * m is the extension header mbuf
 167  * mp is the previous mbuf in the chain
 168  * p is the next header
 169  * i is the type of option.
 170  */
 171 #define MAKE_CHAIN(m, mp, p, i)\
 172     do {\
 173         if (m) {\
 174                 if (!hdrsplit) \
 175                         panic("assumption failed: hdr not split"); \
 176                 *mtod((m), u_char *) = *(p);\
 177                 *(p) = (i);\
 178                 p = mtod((m), u_char *);\
 179                 (m)->m_next = (mp)->m_next;\
 180                 (mp)->m_next = (m);\
 181                 (mp) = (m);\
 182         }\
 183     } while (/*CONSTCOND*/ 0)
 184
 185 /*
 186  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 187  * header (with pri, len, nxt, hlim, src, dst).
 188  * This function may modify ver and hlim only.
 189  * The mbuf chain containing the packet will be freed.
 190  * The mbuf opt, if present, will not be freed.
 191  *
 192  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
 193  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 194  * which is rt_rmx.rmx_mtu.
 195  *
 196  * ifpp - XXX: just for statistics
 197  */
 198 int
 199 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 200     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 201     struct ifnet **ifpp, struct inpcb *inp)
 202 {
 203         struct ip6_hdr *ip6, *mhip6;
 204         struct ifnet *ifp, *origifp;
 205         struct mbuf *m = m0;
 206         struct mbuf *mprev = NULL;
 207         int hlen, tlen, len, off;
 208         struct route_in6 ip6route;
 209         struct rtentry *rt = NULL;
 210         struct sockaddr_in6 *dst, src_sa, dst_sa;
 211         struct in6_addr odst;
 212         int error = 0;
 213         struct in6_ifaddr *ia = NULL;
 214         u_long mtu;
 215         int alwaysfrag, dontfrag;
 216         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 217         struct ip6_exthdrs exthdrs;
 218         struct in6_addr finaldst, src0, dst0;
 219         u_int32_t zone;
 220         struct route_in6 *ro_pmtu = NULL;
 221         int flevalid = 0;
 222         int hdrsplit = 0;
 223         int needipsec = 0;
 224 #ifdef SCTP
 225         int sw_csum;
 226 #endif
 227 #ifdef IPSEC
 228         struct ipsec_output_state state;
 229         struct ip6_rthdr *rh = NULL;
 230         int needipsectun = 0;
 231         int segleft_org = 0;
 232         struct secpolicy *sp = NULL;
 233 #endif /* IPSEC */
 234 #ifdef IPFIREWALL_FORWARD
 235         struct m_tag *fwd_tag;
 236 #endif
 237
 238         ip6 = mtod(m, struct ip6_hdr *);
 239         if (ip6 == NULL) {
 240                 printf ("ip6 is NULL");
 241                 goto bad;
 242         }
 243
 244         finaldst = ip6->ip6_dst;
 245         bzero(&exthdrs, sizeof(exthdrs));
 246         if (opt) {
 247                 /* Hop-by-Hop options header */
 248                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 249                 /* Destination options header(1st part) */
 250                 if (opt->ip6po_rthdr) {
 251                         /*
 252                          * Destination options header(1st part)
 253                          * This only makes sense with a routing header.
 254                          * See Section 9.2 of RFC 3542.
 255                          * Disabling this part just for MIP6 convenience is
 256                          * a bad idea.  We need to think carefully about a
 257                          * way to make the advanced API coexist with MIP6
 258                          * options, which might automatically be inserted in
 259                          * the kernel.
 260                          */
 261                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 262                 }
 263                 /* Routing header */
 264                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 265                 /* Destination options header(2nd part) */
 266                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 267         }
 268
 269         /*
 270          * IPSec checking which handles several cases.
 271          * FAST IPSEC: We re-injected the packet.
 272          */
 273 #ifdef IPSEC
 274         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
 275         {
 276         case 1:                 /* Bad packet */
 277                 goto freehdrs;
 278         case -1:                /* Do IPSec */
 279                 needipsec = 1;
 280         case 0:                 /* No IPSec */
 281         default:
 282                 break;
 283         }
 284 #endif /* IPSEC */
 285
 286         /*
 287          * Calculate the total length of the extension header chain.
 288          * Keep the length of the unfragmentable part for fragmentation.
 289          */
 290         optlen = 0;
 291         if (exthdrs.ip6e_hbh)
 292                 optlen += exthdrs.ip6e_hbh->m_len;
 293         if (exthdrs.ip6e_dest1)
 294                 optlen += exthdrs.ip6e_dest1->m_len;
 295         if (exthdrs.ip6e_rthdr)
 296                 optlen += exthdrs.ip6e_rthdr->m_len;
 297         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 298
 299         /* NOTE: we don't add AH/ESP length here. do that later. */
 300         if (exthdrs.ip6e_dest2)
 301                 optlen += exthdrs.ip6e_dest2->m_len;
 302
 303         /*
 304          * If we need IPsec, or there is at least one extension header,
 305          * separate IP6 header from the payload.
 306          */
 307         if ((needipsec || optlen) && !hdrsplit) {
 308                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 309                         m = NULL;
 310                         goto freehdrs;
 311                 }
 312                 m = exthdrs.ip6e_ip6;
 313                 hdrsplit++;
 314         }
 315
 316         /* adjust pointer */
 317         ip6 = mtod(m, struct ip6_hdr *);
 318
 319         /* adjust mbuf packet header length */
 320         m->m_pkthdr.len += optlen;
 321         plen = m->m_pkthdr.len - sizeof(*ip6);
 322
 323         /* If this is a jumbo payload, insert a jumbo payload option. */
 324         if (plen > IPV6_MAXPACKET) {
 325                 if (!hdrsplit) {
 326                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 327                                 m = NULL;
 328                                 goto freehdrs;
 329                         }
 330                         m = exthdrs.ip6e_ip6;
 331                         hdrsplit++;
 332                 }
 333                 /* adjust pointer */
 334                 ip6 = mtod(m, struct ip6_hdr *);
 335                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 336                         goto freehdrs;
 337                 ip6->ip6_plen = 0;
 338         } else
 339                 ip6->ip6_plen = htons(plen);
 340
 341         /*
 342          * Concatenate headers and fill in next header fields.
 343          * Here we have, on "m"
 344          *      IPv6 payload
 345          * and we insert headers accordingly.  Finally, we should be getting:
 346          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 347          *
 348          * during the header composing process, "m" points to IPv6 header.
 349          * "mprev" points to an extension header prior to esp.
 350          */
 351         u_char *nexthdrp = &ip6->ip6_nxt;
 352         mprev = m;
 353
 354         /*
 355          * we treat dest2 specially.  this makes IPsec processing
 356          * much easier.  the goal here is to make mprev point the
 357          * mbuf prior to dest2.
 358          *
 359          * result: IPv6 dest2 payload
 360          * m and mprev will point to IPv6 header.
 361          */
 362         if (exthdrs.ip6e_dest2) {
 363                 if (!hdrsplit)
 364                         panic("assumption failed: hdr not split");
 365                 exthdrs.ip6e_dest2->m_next = m->m_next;
 366                 m->m_next = exthdrs.ip6e_dest2;
 367                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 368                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 369         }
 370
 371         /*
 372          * result: IPv6 hbh dest1 rthdr dest2 payload
 373          * m will point to IPv6 header.  mprev will point to the
 374          * extension header prior to dest2 (rthdr in the above case).
 375          */
 376         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 377         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 378                    IPPROTO_DSTOPTS);
 379         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 380                    IPPROTO_ROUTING);
 381
 382 #ifdef IPSEC
 383         if (!needipsec)
 384                 goto skip_ipsec2;
 385
 386         /*
 387          * pointers after IPsec headers are not valid any more.
 388          * other pointers need a great care too.
 389          * (IPsec routines should not mangle mbufs prior to AH/ESP)
 390          */
 391         exthdrs.ip6e_dest2 = NULL;
 392
 393         if (exthdrs.ip6e_rthdr) {
 394                 rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
 395                 segleft_org = rh->ip6r_segleft;
 396                 rh->ip6r_segleft = 0;
 397         }
 398
 399         bzero(&state, sizeof(state));
 400         state.m = m;
 401         error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
 402                                     &needipsectun);
 403         m = state.m;
 404         if (error == EJUSTRETURN) {
 405                 /*
 406                  * We had a SP with a level of 'use' and no SA. We
 407                  * will just continue to process the packet without
 408                  * IPsec processing.
 409                  */
 410                 ;
 411         } else if (error) {
 412                 /* mbuf is already reclaimed in ipsec6_output_trans. */
 413                 m = NULL;
 414                 switch (error) {
 415                 case EHOSTUNREACH:
 416                 case ENETUNREACH:
 417                 case EMSGSIZE:
 418                 case ENOBUFS:
 419                 case ENOMEM:
 420                         break;
 421                 default:
 422                         printf("[%s:%d] (ipsec): error code %d\n",
 423                             __func__, __LINE__, error);
 424                         /* FALLTHROUGH */
 425                 case ENOENT:
 426                         /* don't show these error codes to the user */
 427                         error = 0;
 428                         break;
 429                 }
 430                 goto bad;
 431         } else if (!needipsectun) {
 432                 /*
 433                  * In the FAST IPSec case we have already
 434                  * re-injected the packet and it has been freed
 435                  * by the ipsec_done() function.  So, just clean
 436                  * up after ourselves.
 437                  */
 438                 m = NULL;
 439                 goto done;
 440         }
 441         if (exthdrs.ip6e_rthdr) {
 442                 /* ah6_output doesn't modify mbuf chain */
 443                 rh->ip6r_segleft = segleft_org;
 444         }
 445 skip_ipsec2:;
 446 #endif /* IPSEC */
 447
 448         /*
 449          * If there is a routing header, discard the packet.
 450          */
 451         if (exthdrs.ip6e_rthdr) {
 452                  error = EINVAL;
 453                  goto bad;
 454         }
 455
 456         /* Source address validation */
 457         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 458             (flags & IPV6_UNSPECSRC) == 0) {
 459                 error = EOPNOTSUPP;
 460                 V_ip6stat.ip6s_badscope++;
 461                 goto bad;
 462         }
 463         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 464                 error = EOPNOTSUPP;
 465                 V_ip6stat.ip6s_badscope++;
 466                 goto bad;
 467         }
 468
 469         V_ip6stat.ip6s_localout++;
 470
 471         /*
 472          * Route packet.
 473          */
 474         if (ro == 0) {
 475                 ro = &ip6route;
 476                 bzero((caddr_t)ro, sizeof(*ro));
 477         }
 478         ro_pmtu = ro;
 479         if (opt && opt->ip6po_rthdr)
 480                 ro = &opt->ip6po_route;
 481         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 482 #ifdef FLOWTABLE
 483         if (ro == &ip6route) {
 484                 struct flentry *fle;
 485
 486                 /*
 487                  * The flow table returns route entries valid for up to 30
 488                  * seconds; we rely on the remainder of ip_output() taking no
 489                  * longer than that long for the stability of ro_rt.  The
 490                  * flow ID assignment must have happened before this point.
 491                  */
 492                 if ((fle = flowtable_lookup_mbuf(V_ip6_ft, m, AF_INET6)) != NULL) {
 493                         flow_to_route_in6(fle, ro);
 494                         if (ro->ro_rt != NULL && ro->ro_lle != NULL)
 495                                 flevalid = 1;
 496                 }
 497         }
 498 #endif
 499 again:
 500         /*
 501          * if specified, try to fill in the traffic class field.
 502          * do not override if a non-zero value is already set.
 503          * we check the diffserv field and the ecn field separately.
 504          */
 505         if (opt && opt->ip6po_tclass >= 0) {
 506                 int mask = 0;
 507
 508                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 509                         mask |= 0xfc;
 510                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 511                         mask |= 0x03;
 512                 if (mask != 0)
 513                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 514         }
 515
 516         /* fill in or override the hop limit field, if necessary. */
 517         if (opt && opt->ip6po_hlim != -1)
 518                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 519         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 520                 if (im6o != NULL)
 521                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 522                 else
 523                         ip6->ip6_hlim = V_ip6_defmcasthlim;
 524         }
 525
 526 #ifdef IPSEC
 527         /*
 528          * We may re-inject packets into the stack here.
 529          */
 530         if (needipsec && needipsectun) {
 531                 struct ipsec_output_state state;
 532
 533                 /*
 534                  * All the extension headers will become inaccessible
 535                  * (since they can be encrypted).
 536                  * Don't panic, we need no more updates to extension headers
 537                  * on inner IPv6 packet (since they are now encapsulated).
 538                  *
 539                  * IPv6 [ESP|AH] IPv6 [extension headers] payload
 540                  */
 541                 bzero(&exthdrs, sizeof(exthdrs));
 542                 exthdrs.ip6e_ip6 = m;
 543
 544                 bzero(&state, sizeof(state));
 545                 state.m = m;
 546                 state.ro = (struct route *)ro;
 547                 state.dst = (struct sockaddr *)dst;
 548
 549                 error = ipsec6_output_tunnel(&state, sp, flags);
 550
 551                 m = state.m;
 552                 ro = (struct route_in6 *)state.ro;
 553                 dst = (struct sockaddr_in6 *)state.dst;
 554                 if (error == EJUSTRETURN) {
 555                         /*
 556                          * We had a SP with a level of 'use' and no SA. We
 557                          * will just continue to process the packet without
 558                          * IPsec processing.
 559                          */
 560                         ;
 561                 } else if (error) {
 562                         /* mbuf is already reclaimed in ipsec6_output_tunnel. */
 563                         m0 = m = NULL;
 564                         m = NULL;
 565                         switch (error) {
 566                         case EHOSTUNREACH:
 567                         case ENETUNREACH:
 568                         case EMSGSIZE:
 569                         case ENOBUFS:
 570                         case ENOMEM:
 571                                 break;
 572                         default:
 573                                 printf("[%s:%d] (ipsec): error code %d\n",
 574                                     __func__, __LINE__, error);
 575                                 /* FALLTHROUGH */
 576                         case ENOENT:
 577                                 /* don't show these error codes to the user */
 578                                 error = 0;
 579                                 break;
 580                         }
 581                         goto bad;
 582                 } else {
 583                         /*
 584                          * In the FAST IPSec case we have already
 585                          * re-injected the packet and it has been freed
 586                          * by the ipsec_done() function.  So, just clean
 587                          * up after ourselves.
 588                          */
 589                         m = NULL;
 590                         goto done;
 591                 }
 592
 593                 exthdrs.ip6e_ip6 = m;
 594         }
 595 #endif /* IPSEC */
 596
 597         /* adjust pointer */
 598         ip6 = mtod(m, struct ip6_hdr *);
 599
 600         bzero(&dst_sa, sizeof(dst_sa));
 601         dst_sa.sin6_family = AF_INET6;
 602         dst_sa.sin6_len = sizeof(dst_sa);
 603         dst_sa.sin6_addr = ip6->ip6_dst;
 604         if (flevalid) {
 605                 rt = ro->ro_rt;
 606                 ifp = ro->ro_rt->rt_ifp;
 607         } else if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
 608             &ifp, &rt)) != 0) {
 609                 switch (error) {
 610                 case EHOSTUNREACH:
 611                         V_ip6stat.ip6s_noroute++;
 612                         break;
 613                 case EADDRNOTAVAIL:
 614                 default:
 615                         break; /* XXX statistics? */
 616                 }
 617                 if (ifp != NULL)
 618                         in6_ifstat_inc(ifp, ifs6_out_discard);
 619                 goto bad;
 620         }
 621         if (rt == NULL) {
 622                 /*
 623                  * If in6_selectroute() does not return a route entry,
 624                  * dst may not have been updated.
 625                  */
 626                 *dst = dst_sa;  /* XXX */
 627         }
 628
 629         /*
 630          * then rt (for unicast) and ifp must be non-NULL valid values.
 631          */
 632         if ((flags & IPV6_FORWARDING) == 0) {
 633                 /* XXX: the FORWARDING flag can be set for mrouting. */
 634                 in6_ifstat_inc(ifp, ifs6_out_request);
 635         }
 636         if (rt != NULL) {
 637                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 638                 rt->rt_use++;
 639         }
 640
 641
 642         /*
 643          * The outgoing interface must be in the zone of source and
 644          * destination addresses.
 645          */
 646         origifp = ifp;
 647
 648         src0 = ip6->ip6_src;
 649         if (in6_setscope(&src0, origifp, &zone))
 650                 goto badscope;
 651         bzero(&src_sa, sizeof(src_sa));
 652         src_sa.sin6_family = AF_INET6;
 653         src_sa.sin6_len = sizeof(src_sa);
 654         src_sa.sin6_addr = ip6->ip6_src;
 655         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 656                 goto badscope;
 657
 658         dst0 = ip6->ip6_dst;
 659         if (in6_setscope(&dst0, origifp, &zone))
 660                 goto badscope;
 661         /* re-initialize to be sure */
 662         bzero(&dst_sa, sizeof(dst_sa));
 663         dst_sa.sin6_family = AF_INET6;
 664         dst_sa.sin6_len = sizeof(dst_sa);
 665         dst_sa.sin6_addr = ip6->ip6_dst;
 666         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 667                 goto badscope;
 668         }
 669
 670         /* We should use ia_ifp to support the case of
 671          * sending packets to an address of our own.
 672          */
 673         if (ia != NULL && ia->ia_ifp)
 674                 ifp = ia->ia_ifp;
 675
 676         /* scope check is done. */
 677         goto routefound;
 678
 679   badscope:
 680         V_ip6stat.ip6s_badscope++;
 681         in6_ifstat_inc(origifp, ifs6_out_discard);
 682         if (error == 0)
 683                 error = EHOSTUNREACH; /* XXX */
 684         goto bad;
 685
 686   routefound:
 687         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 688                 if (opt && opt->ip6po_nextroute.ro_rt) {
 689                         /*
 690                          * The nexthop is explicitly specified by the
 691                          * application.  We assume the next hop is an IPv6
 692                          * address.
 693                          */
 694                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 695                 }
 696                 else if ((rt->rt_flags & RTF_GATEWAY))
 697                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 698         }
 699
 700         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 701                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 702         } else {
 703                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 704                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 705                 /*
 706                  * Confirm that the outgoing interface supports multicast.
 707                  */
 708                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 709                         V_ip6stat.ip6s_noroute++;
 710                         in6_ifstat_inc(ifp, ifs6_out_discard);
 711                         error = ENETUNREACH;
 712                         goto bad;
 713                 }
 714                 if ((im6o == NULL && in6_mcast_loop) ||
 715                     (im6o && im6o->im6o_multicast_loop)) {
 716                         /*
 717                          * Loop back multicast datagram if not expressly
 718                          * forbidden to do so, even if we have not joined
 719                          * the address; protocols will filter it later,
 720                          * thus deferring a hash lookup and lock acquisition
 721                          * at the expense of an m_copym().
 722                          */
 723                         ip6_mloopback(ifp, m, dst);
 724                 } else {
 725                         /*
 726                          * If we are acting as a multicast router, perform
 727                          * multicast forwarding as if the packet had just
 728                          * arrived on the interface to which we are about
 729                          * to send.  The multicast forwarding function
 730                          * recursively calls this function, using the
 731                          * IPV6_FORWARDING flag to prevent infinite recursion.
 732                          *
 733                          * Multicasts that are looped back by ip6_mloopback(),
 734                          * above, will be forwarded by the ip6_input() routine,
 735                          * if necessary.
 736                          */
 737                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 738                                 /*
 739                                  * XXX: ip6_mforward expects that rcvif is NULL
 740                                  * when it is called from the originating path.
 741                                  * However, it is not always the case, since
 742                                  * some versions of MGETHDR() does not
 743                                  * initialize the field.
 744                                  */
 745                                 m->m_pkthdr.rcvif = NULL;
 746                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 747                                         m_freem(m);
 748                                         goto done;
 749                                 }
 750                         }
 751                 }
 752                 /*
 753                  * Multicasts with a hoplimit of zero may be looped back,
 754                  * above, but must not be transmitted on a network.
 755                  * Also, multicasts addressed to the loopback interface
 756                  * are not sent -- the above call to ip6_mloopback() will
 757                  * loop back a copy if this host actually belongs to the
 758                  * destination group on the loopback interface.
 759                  */
 760                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 761                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 762                         m_freem(m);
 763                         goto done;
 764                 }
 765         }
 766
 767         /*
 768          * Fill the outgoing inteface to tell the upper layer
 769          * to increment per-interface statistics.
 770          */
 771         if (ifpp)
 772                 *ifpp = ifp;
 773
 774         /* Determine path MTU. */
 775         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
 776             &alwaysfrag)) != 0)
 777                 goto bad;
 778
 779         /*
 780          * The caller of this function may specify to use the minimum MTU
 781          * in some cases.
 782          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 783          * setting.  The logic is a bit complicated; by default, unicast
 784          * packets will follow path MTU while multicast packets will be sent at
 785          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 786          * including unicast ones will be sent at the minimum MTU.  Multicast
 787          * packets will always be sent at the minimum MTU unless
 788          * IP6PO_MINMTU_DISABLE is explicitly specified.
 789          * See RFC 3542 for more details.
 790          */
 791         if (mtu > IPV6_MMTU) {
 792                 if ((flags & IPV6_MINMTU))
 793                         mtu = IPV6_MMTU;
 794                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 795                         mtu = IPV6_MMTU;
 796                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 797                          (opt == NULL ||
 798                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 799                         mtu = IPV6_MMTU;
 800                 }
 801         }
 802
 803         /*
 804          * clear embedded scope identifiers if necessary.
 805          * in6_clearscope will touch the addresses only when necessary.
 806          */
 807         in6_clearscope(&ip6->ip6_src);
 808         in6_clearscope(&ip6->ip6_dst);
 809
 810         /*
 811          * If the outgoing packet contains a hop-by-hop options header,
 812          * it must be examined and processed even by the source node.
 813          * (RFC 2460, section 4.)
 814          */
 815         if (exthdrs.ip6e_hbh) {
 816                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 817                 u_int32_t dummy; /* XXX unused */
 818                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 819
 820 #ifdef DIAGNOSTIC
 821                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 822                         panic("ip6e_hbh is not contiguous");
 823 #endif
 824                 /*
 825                  *  XXX: if we have to send an ICMPv6 error to the sender,
 826                  *       we need the M_LOOP flag since icmp6_error() expects
 827                  *       the IPv6 and the hop-by-hop options header are
 828                  *       contiguous unless the flag is set.
 829                  */
 830                 m->m_flags |= M_LOOP;
 831                 m->m_pkthdr.rcvif = ifp;
 832                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 833                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 834                     &dummy, &plen) < 0) {
 835                         /* m was already freed at this point */
 836                         error = EINVAL;/* better error? */
 837                         goto done;
 838                 }
 839                 m->m_flags &= ~M_LOOP; /* XXX */
 840                 m->m_pkthdr.rcvif = NULL;
 841         }
 842
 843         /* Jump over all PFIL processing if hooks are not active. */
 844         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
 845                 goto passout;
 846
 847         odst = ip6->ip6_dst;
 848         /* Run through list of hooks for output packets. */
 849         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 850         if (error != 0 || m == NULL)
 851                 goto done;
 852         ip6 = mtod(m, struct ip6_hdr *);
 853
 854         /* See if destination IP address was changed by packet filter. */
 855         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 856                 m->m_flags |= M_SKIP_FIREWALL;
 857                 /* If destination is now ourself drop to ip6_input(). */
 858                 if (in6_localip(&ip6->ip6_dst)) {
 859                         m->m_flags |= M_FASTFWD_OURS;
 860                         if (m->m_pkthdr.rcvif == NULL)
 861                                 m->m_pkthdr.rcvif = V_loif;
 862                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 863                                 m->m_pkthdr.csum_flags |=
 864                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 865                                 m->m_pkthdr.csum_data = 0xffff;
 866                         }
 867                         m->m_pkthdr.csum_flags |=
 868                             CSUM_IP_CHECKED | CSUM_IP_VALID;
 869 #ifdef SCTP
 870                         if (m->m_pkthdr.csum_flags & CSUM_SCTP)
 871                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 872 #endif
 873                         error = netisr_queue(NETISR_IPV6, m);
 874                         goto done;
 875                 } else
 876                         goto again;     /* Redo the routing table lookup. */
 877         }
 878
 879 #ifdef IPFIREWALL_FORWARD
 880         /* See if local, if yes, send it to netisr. */
 881         if (m->m_flags & M_FASTFWD_OURS) {
 882                 if (m->m_pkthdr.rcvif == NULL)
 883                         m->m_pkthdr.rcvif = V_loif;
 884                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 885                         m->m_pkthdr.csum_flags |=
 886                             CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 887                         m->m_pkthdr.csum_data = 0xffff;
 888                 }
 889 #ifdef SCTP
 890                 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
 891                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 892 #endif
 893                 error = netisr_queue(NETISR_IPV6, m);
 894                 goto done;
 895         }
 896         /* Or forward to some other address? */
 897         fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 898         if (fwd_tag) {
 899                 dst = (struct sockaddr_in6 *)&ro->ro_dst;
 900                 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6));
 901                 m->m_flags |= M_SKIP_FIREWALL;
 902                 m_tag_delete(m, fwd_tag);
 903                 goto again;
 904         }
 905 #endif /* IPFIREWALL_FORWARD */
 906
 907 passout:
 908         /*
 909          * Send the packet to the outgoing interface.
 910          * If necessary, do IPv6 fragmentation before sending.
 911          *
 912          * the logic here is rather complex:
 913          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 914          * 1-a: send as is if tlen <= path mtu
 915          * 1-b: fragment if tlen > path mtu
 916          *
 917          * 2: if user asks us not to fragment (dontfrag == 1)
 918          * 2-a: send as is if tlen <= interface mtu
 919          * 2-b: error if tlen > interface mtu
 920          *
 921          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 922          *      always fragment
 923          *
 924          * 4: if dontfrag == 1 && alwaysfrag == 1
 925          *      error, as we cannot handle this conflicting request
 926          */
 927 #ifdef SCTP
 928         sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
 929         if (sw_csum & CSUM_SCTP) {
 930                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 931                 sw_csum &= ~CSUM_SCTP;
 932         }
 933 #endif
 934         tlen = m->m_pkthdr.len;
 935
 936         if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
 937                 dontfrag = 1;
 938         else
 939                 dontfrag = 0;
 940         if (dontfrag && alwaysfrag) {   /* case 4 */
 941                 /* conflicting request - can't transmit */
 942                 error = EMSGSIZE;
 943                 goto bad;
 944         }
 945         if (dontfrag && tlen > IN6_LINKMTU(ifp)) {      /* case 2-b */
 946                 /*
 947                  * Even if the DONTFRAG option is specified, we cannot send the
 948                  * packet when the data length is larger than the MTU of the
 949                  * outgoing interface.
 950                  * Notify the error by sending IPV6_PATHMTU ancillary data as
 951                  * well as returning an error code (the latter is not described
 952                  * in the API spec.)
 953                  */
 954                 u_int32_t mtu32;
 955                 struct ip6ctlparam ip6cp;
 956
 957                 mtu32 = (u_int32_t)mtu;
 958                 bzero(&ip6cp, sizeof(ip6cp));
 959                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
 960                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
 961                     (void *)&ip6cp);
 962
 963                 error = EMSGSIZE;
 964                 goto bad;
 965         }
 966
 967         /*
 968          * transmit packet without fragmentation
 969          */
 970         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 971                 struct in6_ifaddr *ia6;
 972
 973                 ip6 = mtod(m, struct ip6_hdr *);
 974                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 975                 if (ia6) {
 976                         /* Record statistics for this interface address. */
 977                         ia6->ia_ifa.if_opackets++;
 978                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
 979                         ifa_free(&ia6->ia_ifa);
 980                 }
 981                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
 982                 goto done;
 983         }
 984
 985         /*
 986          * try to fragment the packet.  case 1-b and 3
 987          */
 988         if (mtu < IPV6_MMTU) {
 989                 /* path MTU cannot be less than IPV6_MMTU */
 990                 error = EMSGSIZE;
 991                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 992                 goto bad;
 993         } else if (ip6->ip6_plen == 0) {
 994                 /* jumbo payload cannot be fragmented */
 995                 error = EMSGSIZE;
 996                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 997                 goto bad;
 998         } else {
 999                 struct mbuf **mnext, *m_frgpart;
1000                 struct ip6_frag *ip6f;
1001                 u_int32_t id = htonl(ip6_randomid());
1002                 u_char nextproto;
1003
1004                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
1005
1006                 /*
1007                  * Too large for the destination or interface;
1008                  * fragment if possible.
1009                  * Must be able to put at least 8 bytes per fragment.
1010                  */
1011                 hlen = unfragpartlen;
1012                 if (mtu > IPV6_MAXPACKET)
1013                         mtu = IPV6_MAXPACKET;
1014
1015                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
1016                 if (len < 8) {
1017                         error = EMSGSIZE;
1018                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
1019                         goto bad;
1020                 }
1021
1022                 /*
1023                  * Verify that we have any chance at all of being able to queue
1024                  *      the packet or packet fragments
1025                  */
1026                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
1027                     < tlen  /* - hlen */)) {
1028                         error = ENOBUFS;
1029                         V_ip6stat.ip6s_odropped++;
1030                         goto bad;
1031                 }
1032
1033                 mnext = &m->m_nextpkt;
1034
1035                 /*
1036                  * Change the next header field of the last header in the
1037                  * unfragmentable part.
1038                  */
1039                 if (exthdrs.ip6e_rthdr) {
1040                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1041                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1042                 } else if (exthdrs.ip6e_dest1) {
1043                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1044                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1045                 } else if (exthdrs.ip6e_hbh) {
1046                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1047                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1048                 } else {
1049                         nextproto = ip6->ip6_nxt;
1050                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
1051                 }
1052
1053                 /*
1054                  * Loop through length of segment after first fragment,
1055                  * make new header and copy data of each part and link onto
1056                  * chain.
1057                  */
1058                 m0 = m;
1059                 for (off = hlen; off < tlen; off += len) {
1060                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
1061                         if (!m) {
1062                                 error = ENOBUFS;
1063                                 V_ip6stat.ip6s_odropped++;
1064                                 goto sendorfree;
1065                         }
1066                         m->m_pkthdr.rcvif = NULL;
1067                         m->m_flags = m0->m_flags & M_COPYFLAGS;
1068                         *mnext = m;
1069                         mnext = &m->m_nextpkt;
1070                         m->m_data += max_linkhdr;
1071                         mhip6 = mtod(m, struct ip6_hdr *);
1072                         *mhip6 = *ip6;
1073                         m->m_len = sizeof(*mhip6);
1074                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1075                         if (error) {
1076                                 V_ip6stat.ip6s_odropped++;
1077                                 goto sendorfree;
1078                         }
1079                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1080                         if (off + len >= tlen)
1081                                 len = tlen - off;
1082                         else
1083                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1084                         mhip6->ip6_plen = htons((u_short)(len + hlen +
1085                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1086                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1087                                 error = ENOBUFS;
1088                                 V_ip6stat.ip6s_odropped++;
1089                                 goto sendorfree;
1090                         }
1091                         m_cat(m, m_frgpart);
1092                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1093                         m->m_pkthdr.rcvif = NULL;
1094                         ip6f->ip6f_reserved = 0;
1095                         ip6f->ip6f_ident = id;
1096                         ip6f->ip6f_nxt = nextproto;
1097                         V_ip6stat.ip6s_ofragments++;
1098                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1099                 }
1100
1101                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1102         }
1103
1104         /*
1105          * Remove leading garbages.
1106          */
1107 sendorfree:
1108         m = m0->m_nextpkt;
1109         m0->m_nextpkt = 0;
1110         m_freem(m0);
1111         for (m0 = m; m; m = m0) {
1112                 m0 = m->m_nextpkt;
1113                 m->m_nextpkt = 0;
1114                 if (error == 0) {
1115                         /* Record statistics for this interface address. */
1116                         if (ia) {
1117                                 ia->ia_ifa.if_opackets++;
1118                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1119                         }
1120                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1121                 } else
1122                         m_freem(m);
1123         }
1124
1125         if (error == 0)
1126                 V_ip6stat.ip6s_fragmented++;
1127
1128 done:
1129         if (ro == &ip6route && ro->ro_rt && flevalid == 0) {
1130                 /* brace necessary for RTFREE */
1131                 RTFREE(ro->ro_rt);
1132         } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt &&
1133             ((flevalid == 0) || (ro_pmtu != ro))) {
1134                 RTFREE(ro_pmtu->ro_rt);
1135         }
1136 #ifdef IPSEC
1137         if (sp != NULL)
1138                 KEY_FREESP(&sp);
1139 #endif
1140
1141         return (error);
1142
1143 freehdrs:
1144         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1145         m_freem(exthdrs.ip6e_dest1);
1146         m_freem(exthdrs.ip6e_rthdr);
1147         m_freem(exthdrs.ip6e_dest2);
1148         /* FALLTHROUGH */
1149 bad:
1150         if (m)
1151                 m_freem(m);
1152         goto done;
1153 }
1154
1155 static int
1156 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1157 {
1158         struct mbuf *m;
1159
1160         if (hlen > MCLBYTES)
1161                 return (ENOBUFS); /* XXX */
1162
1163         MGET(m, M_DONTWAIT, MT_DATA);
1164         if (!m)
1165                 return (ENOBUFS);
1166
1167         if (hlen > MLEN) {
1168                 MCLGET(m, M_DONTWAIT);
1169                 if ((m->m_flags & M_EXT) == 0) {
1170                         m_free(m);
1171                         return (ENOBUFS);
1172                 }
1173         }
1174         m->m_len = hlen;
1175         if (hdr)
1176                 bcopy(hdr, mtod(m, caddr_t), hlen);
1177
1178         *mp = m;
1179         return (0);
1180 }
1181
1182 /*
1183  * Insert jumbo payload option.
1184  */
1185 static int
1186 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1187 {
1188         struct mbuf *mopt;
1189         u_char *optbuf;
1190         u_int32_t v;
1191
1192 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1193
1194         /*
1195          * If there is no hop-by-hop options header, allocate new one.
1196          * If there is one but it doesn't have enough space to store the
1197          * jumbo payload option, allocate a cluster to store the whole options.
1198          * Otherwise, use it to store the options.
1199          */
1200         if (exthdrs->ip6e_hbh == 0) {
1201                 MGET(mopt, M_DONTWAIT, MT_DATA);
1202                 if (mopt == 0)
1203                         return (ENOBUFS);
1204                 mopt->m_len = JUMBOOPTLEN;
1205                 optbuf = mtod(mopt, u_char *);
1206                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1207                 exthdrs->ip6e_hbh = mopt;
1208         } else {
1209                 struct ip6_hbh *hbh;
1210
1211                 mopt = exthdrs->ip6e_hbh;
1212                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1213                         /*
1214                          * XXX assumption:
1215                          * - exthdrs->ip6e_hbh is not referenced from places
1216                          *   other than exthdrs.
1217                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1218                          */
1219                         int oldoptlen = mopt->m_len;
1220                         struct mbuf *n;
1221
1222                         /*
1223                          * XXX: give up if the whole (new) hbh header does
1224                          * not fit even in an mbuf cluster.
1225                          */
1226                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1227                                 return (ENOBUFS);
1228
1229                         /*
1230                          * As a consequence, we must always prepare a cluster
1231                          * at this point.
1232                          */
1233                         MGET(n, M_DONTWAIT, MT_DATA);
1234                         if (n) {
1235                                 MCLGET(n, M_DONTWAIT);
1236                                 if ((n->m_flags & M_EXT) == 0) {
1237                                         m_freem(n);
1238                                         n = NULL;
1239                                 }
1240                         }
1241                         if (!n)
1242                                 return (ENOBUFS);
1243                         n->m_len = oldoptlen + JUMBOOPTLEN;
1244                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1245                             oldoptlen);
1246                         optbuf = mtod(n, caddr_t) + oldoptlen;
1247                         m_freem(mopt);
1248                         mopt = exthdrs->ip6e_hbh = n;
1249                 } else {
1250                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1251                         mopt->m_len += JUMBOOPTLEN;
1252                 }
1253                 optbuf[0] = IP6OPT_PADN;
1254                 optbuf[1] = 1;
1255
1256                 /*
1257                  * Adjust the header length according to the pad and
1258                  * the jumbo payload option.
1259                  */
1260                 hbh = mtod(mopt, struct ip6_hbh *);
1261                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1262         }
1263
1264         /* fill in the option. */
1265         optbuf[2] = IP6OPT_JUMBO;
1266         optbuf[3] = 4;
1267         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1268         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1269
1270         /* finally, adjust the packet header length */
1271         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1272
1273         return (0);
1274 #undef JUMBOOPTLEN
1275 }
1276
1277 /*
1278  * Insert fragment header and copy unfragmentable header portions.
1279  */
1280 static int
1281 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1282     struct ip6_frag **frghdrp)
1283 {
1284         struct mbuf *n, *mlast;
1285
1286         if (hlen > sizeof(struct ip6_hdr)) {
1287                 n = m_copym(m0, sizeof(struct ip6_hdr),
1288                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
1289                 if (n == 0)
1290                         return (ENOBUFS);
1291                 m->m_next = n;
1292         } else
1293                 n = m;
1294
1295         /* Search for the last mbuf of unfragmentable part. */
1296         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1297                 ;
1298
1299         if ((mlast->m_flags & M_EXT) == 0 &&
1300             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1301                 /* use the trailing space of the last mbuf for the fragment hdr */
1302                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1303                     mlast->m_len);
1304                 mlast->m_len += sizeof(struct ip6_frag);
1305                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1306         } else {
1307                 /* allocate a new mbuf for the fragment header */
1308                 struct mbuf *mfrg;
1309
1310                 MGET(mfrg, M_DONTWAIT, MT_DATA);
1311                 if (mfrg == 0)
1312                         return (ENOBUFS);
1313                 mfrg->m_len = sizeof(struct ip6_frag);
1314                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1315                 mlast->m_next = mfrg;
1316         }
1317
1318         return (0);
1319 }
1320
1321 static int
1322 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1323     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1324     int *alwaysfragp)
1325 {
1326         u_int32_t mtu = 0;
1327         int alwaysfrag = 0;
1328         int error = 0;
1329
1330         if (ro_pmtu != ro) {
1331                 /* The first hop and the final destination may differ. */
1332                 struct sockaddr_in6 *sa6_dst =
1333                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1334                 if (ro_pmtu->ro_rt &&
1335                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1336                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1337                         RTFREE(ro_pmtu->ro_rt);
1338                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
1339                 }
1340                 if (ro_pmtu->ro_rt == NULL) {
1341                         bzero(sa6_dst, sizeof(*sa6_dst));
1342                         sa6_dst->sin6_family = AF_INET6;
1343                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1344                         sa6_dst->sin6_addr = *dst;
1345
1346                         rtalloc((struct route *)ro_pmtu);
1347                 }
1348         }
1349         if (ro_pmtu->ro_rt) {
1350                 u_int32_t ifmtu;
1351                 struct in_conninfo inc;
1352
1353                 bzero(&inc, sizeof(inc));
1354                 inc.inc_flags |= INC_ISIPV6;
1355                 inc.inc6_faddr = *dst;
1356
1357                 if (ifp == NULL)
1358                         ifp = ro_pmtu->ro_rt->rt_ifp;
1359                 ifmtu = IN6_LINKMTU(ifp);
1360                 mtu = tcp_hc_getmtu(&inc);
1361                 if (mtu)
1362                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
1363                 else
1364                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1365                 if (mtu == 0)
1366                         mtu = ifmtu;
1367                 else if (mtu < IPV6_MMTU) {
1368                         /*
1369                          * RFC2460 section 5, last paragraph:
1370                          * if we record ICMPv6 too big message with
1371                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1372                          * or smaller, with framgent header attached.
1373                          * (fragment header is needed regardless from the
1374                          * packet size, for translators to identify packets)
1375                          */
1376                         alwaysfrag = 1;
1377                         mtu = IPV6_MMTU;
1378                 } else if (mtu > ifmtu) {
1379                         /*
1380                          * The MTU on the route is larger than the MTU on
1381                          * the interface!  This shouldn't happen, unless the
1382                          * MTU of the interface has been changed after the
1383                          * interface was brought up.  Change the MTU in the
1384                          * route to match the interface MTU (as long as the
1385                          * field isn't locked).
1386                          */
1387                         mtu = ifmtu;
1388                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1389                 }
1390         } else if (ifp) {
1391                 mtu = IN6_LINKMTU(ifp);
1392         } else
1393                 error = EHOSTUNREACH; /* XXX */
1394
1395         *mtup = mtu;
1396         if (alwaysfragp)
1397                 *alwaysfragp = alwaysfrag;
1398         return (error);
1399 }
1400
1401 /*
1402  * IP6 socket option processing.
1403  */
1404 int
1405 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1406 {
1407         int optdatalen, uproto;
1408         void *optdata;
1409         struct inpcb *in6p = sotoinpcb(so);
1410         int error, optval;
1411         int level, op, optname;
1412         int optlen;
1413         struct thread *td;
1414
1415         level = sopt->sopt_level;
1416         op = sopt->sopt_dir;
1417         optname = sopt->sopt_name;
1418         optlen = sopt->sopt_valsize;
1419         td = sopt->sopt_td;
1420         error = 0;
1421         optval = 0;
1422         uproto = (int)so->so_proto->pr_protocol;
1423
1424         if (level != IPPROTO_IPV6) {
1425                 error = EINVAL;
1426
1427                 if (sopt->sopt_level == SOL_SOCKET &&
1428                     sopt->sopt_dir == SOPT_SET) {
1429                         switch (sopt->sopt_name) {
1430                         case SO_REUSEADDR:
1431                                 INP_WLOCK(in6p);
1432                                 if (IN_MULTICAST(ntohl(in6p->inp_laddr.s_addr))) {
1433                                         if ((so->so_options &
1434                                             (SO_REUSEADDR | SO_REUSEPORT)) != 0)
1435                                                 in6p->inp_flags2 |= INP_REUSEPORT;
1436                                         else
1437                                                 in6p->inp_flags2 &= ~INP_REUSEPORT;
1438                                 }
1439                                 INP_WUNLOCK(in6p);
1440                                 error = 0;
1441                                 break;
1442                         case SO_REUSEPORT:
1443                                 INP_WLOCK(in6p);
1444                                 if ((so->so_options & SO_REUSEPORT) != 0)
1445                                         in6p->inp_flags2 |= INP_REUSEPORT;
1446                                 else
1447                                         in6p->inp_flags2 &= ~INP_REUSEPORT;
1448                                 INP_WUNLOCK(in6p);
1449                                 error = 0;
1450                                 break;
1451                         default:
1452                                 break;
1453                         }
1454                 }
1455         } else {                /* level == IPPROTO_IPV6 */
1456                 switch (op) {
1457
1458                 case SOPT_SET:
1459                         switch (optname) {
1460                         case IPV6_2292PKTOPTIONS:
1461 #ifdef IPV6_PKTOPTIONS
1462                         case IPV6_PKTOPTIONS:
1463 #endif
1464                         {
1465                                 struct mbuf *m;
1466
1467                                 error = soopt_getm(sopt, &m); /* XXX */
1468                                 if (error != 0)
1469                                         break;
1470                                 error = soopt_mcopyin(sopt, m); /* XXX */
1471                                 if (error != 0)
1472                                         break;
1473                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1474                                                     m, so, sopt);
1475                                 m_freem(m); /* XXX */
1476                                 break;
1477                         }
1478
1479                         /*
1480                          * Use of some Hop-by-Hop options or some
1481                          * Destination options, might require special
1482                          * privilege.  That is, normal applications
1483                          * (without special privilege) might be forbidden
1484                          * from setting certain options in outgoing packets,
1485                          * and might never see certain options in received
1486                          * packets. [RFC 2292 Section 6]
1487                          * KAME specific note:
1488                          *  KAME prevents non-privileged users from sending or
1489                          *  receiving ANY hbh/dst options in order to avoid
1490                          *  overhead of parsing options in the kernel.
1491                          */
1492                         case IPV6_RECVHOPOPTS:
1493                         case IPV6_RECVDSTOPTS:
1494                         case IPV6_RECVRTHDRDSTOPTS:
1495                                 if (td != NULL) {
1496                                         error = priv_check(td,
1497                                             PRIV_NETINET_SETHDROPTS);
1498                                         if (error)
1499                                                 break;
1500                                 }
1501                                 /* FALLTHROUGH */
1502                         case IPV6_UNICAST_HOPS:
1503                         case IPV6_HOPLIMIT:
1504                         case IPV6_FAITH:
1505
1506                         case IPV6_RECVPKTINFO:
1507                         case IPV6_RECVHOPLIMIT:
1508                         case IPV6_RECVRTHDR:
1509                         case IPV6_RECVPATHMTU:
1510                         case IPV6_RECVTCLASS:
1511                         case IPV6_V6ONLY:
1512                         case IPV6_AUTOFLOWLABEL:
1513                         case IPV6_BINDANY:
1514                                 if (optname == IPV6_BINDANY && td != NULL) {
1515                                         error = priv_check(td,
1516                                             PRIV_NETINET_BINDANY);
1517                                         if (error)
1518                                                 break;
1519                                 }
1520
1521                                 if (optlen != sizeof(int)) {
1522                                         error = EINVAL;
1523                                         break;
1524                                 }
1525                                 error = sooptcopyin(sopt, &optval,
1526                                         sizeof optval, sizeof optval);
1527                                 if (error)
1528                                         break;
1529                                 switch (optname) {
1530
1531                                 case IPV6_UNICAST_HOPS:
1532                                         if (optval < -1 || optval >= 256)
1533                                                 error = EINVAL;
1534                                         else {
1535                                                 /* -1 = kernel default */
1536                                                 in6p->in6p_hops = optval;
1537                                                 if ((in6p->inp_vflag &
1538                                                      INP_IPV4) != 0)
1539                                                         in6p->inp_ip_ttl = optval;
1540                                         }
1541                                         break;
1542 #define OPTSET(bit) \
1543 do { \
1544         if (optval) \
1545                 in6p->inp_flags |= (bit); \
1546         else \
1547                 in6p->inp_flags &= ~(bit); \
1548 } while (/*CONSTCOND*/ 0)
1549 #define OPTSET2292(bit) \
1550 do { \
1551         in6p->inp_flags |= IN6P_RFC2292; \
1552         if (optval) \
1553                 in6p->inp_flags |= (bit); \
1554         else \
1555                 in6p->inp_flags &= ~(bit); \
1556 } while (/*CONSTCOND*/ 0)
1557 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1558
1559                                 case IPV6_RECVPKTINFO:
1560                                         /* cannot mix with RFC2292 */
1561                                         if (OPTBIT(IN6P_RFC2292)) {
1562                                                 error = EINVAL;
1563                                                 break;
1564                                         }
1565                                         OPTSET(IN6P_PKTINFO);
1566                                         break;
1567
1568                                 case IPV6_HOPLIMIT:
1569                                 {
1570                                         struct ip6_pktopts **optp;
1571
1572                                         /* cannot mix with RFC2292 */
1573                                         if (OPTBIT(IN6P_RFC2292)) {
1574                                                 error = EINVAL;
1575                                                 break;
1576                                         }
1577                                         optp = &in6p->in6p_outputopts;
1578                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1579                                             (u_char *)&optval, sizeof(optval),
1580                                             optp, (td != NULL) ? td->td_ucred :
1581                                             NULL, uproto);
1582                                         break;
1583                                 }
1584
1585                                 case IPV6_RECVHOPLIMIT:
1586                                         /* cannot mix with RFC2292 */
1587                                         if (OPTBIT(IN6P_RFC2292)) {
1588                                                 error = EINVAL;
1589                                                 break;
1590                                         }
1591                                         OPTSET(IN6P_HOPLIMIT);
1592                                         break;
1593
1594                                 case IPV6_RECVHOPOPTS:
1595                                         /* cannot mix with RFC2292 */
1596                                         if (OPTBIT(IN6P_RFC2292)) {
1597                                                 error = EINVAL;
1598                                                 break;
1599                                         }
1600                                         OPTSET(IN6P_HOPOPTS);
1601                                         break;
1602
1603                                 case IPV6_RECVDSTOPTS:
1604                                         /* cannot mix with RFC2292 */
1605                                         if (OPTBIT(IN6P_RFC2292)) {
1606                                                 error = EINVAL;
1607                                                 break;
1608                                         }
1609                                         OPTSET(IN6P_DSTOPTS);
1610                                         break;
1611
1612                                 case IPV6_RECVRTHDRDSTOPTS:
1613                                         /* cannot mix with RFC2292 */
1614                                         if (OPTBIT(IN6P_RFC2292)) {
1615                                                 error = EINVAL;
1616                                                 break;
1617                                         }
1618                                         OPTSET(IN6P_RTHDRDSTOPTS);
1619                                         break;
1620
1621                                 case IPV6_RECVRTHDR:
1622                                         /* cannot mix with RFC2292 */
1623                                         if (OPTBIT(IN6P_RFC2292)) {
1624                                                 error = EINVAL;
1625                                                 break;
1626                                         }
1627                                         OPTSET(IN6P_RTHDR);
1628                                         break;
1629
1630                                 case IPV6_FAITH:
1631                                         OPTSET(INP_FAITH);
1632                                         break;
1633
1634                                 case IPV6_RECVPATHMTU:
1635                                         /*
1636                                          * We ignore this option for TCP
1637                                          * sockets.
1638                                          * (RFC3542 leaves this case
1639                                          * unspecified.)
1640                                          */
1641                                         if (uproto != IPPROTO_TCP)
1642                                                 OPTSET(IN6P_MTU);
1643                                         break;
1644
1645                                 case IPV6_V6ONLY:
1646                                         /*
1647                                          * make setsockopt(IPV6_V6ONLY)
1648                                          * available only prior to bind(2).
1649                                          * see ipng mailing list, Jun 22 2001.
1650                                          */
1651                                         if (in6p->inp_lport ||
1652                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1653                                                 error = EINVAL;
1654                                                 break;
1655                                         }
1656                                         OPTSET(IN6P_IPV6_V6ONLY);
1657                                         if (optval)
1658                                                 in6p->inp_vflag &= ~INP_IPV4;
1659                                         else
1660                                                 in6p->inp_vflag |= INP_IPV4;
1661                                         break;
1662                                 case IPV6_RECVTCLASS:
1663                                         /* cannot mix with RFC2292 XXX */
1664                                         if (OPTBIT(IN6P_RFC2292)) {
1665                                                 error = EINVAL;
1666                                                 break;
1667                                         }
1668                                         OPTSET(IN6P_TCLASS);
1669                                         break;
1670                                 case IPV6_AUTOFLOWLABEL:
1671                                         OPTSET(IN6P_AUTOFLOWLABEL);
1672                                         break;
1673
1674                                 case IPV6_BINDANY:
1675                                         OPTSET(INP_BINDANY);
1676                                         break;
1677                                 }
1678                                 break;
1679
1680                         case IPV6_TCLASS:
1681                         case IPV6_DONTFRAG:
1682                         case IPV6_USE_MIN_MTU:
1683                         case IPV6_PREFER_TEMPADDR:
1684                                 if (optlen != sizeof(optval)) {
1685                                         error = EINVAL;
1686                                         break;
1687                                 }
1688                                 error = sooptcopyin(sopt, &optval,
1689                                         sizeof optval, sizeof optval);
1690                                 if (error)
1691                                         break;
1692                                 {
1693                                         struct ip6_pktopts **optp;
1694                                         optp = &in6p->in6p_outputopts;
1695                                         error = ip6_pcbopt(optname,
1696                                             (u_char *)&optval, sizeof(optval),
1697                                             optp, (td != NULL) ? td->td_ucred :
1698                                             NULL, uproto);
1699                                         break;
1700                                 }
1701
1702                         case IPV6_2292PKTINFO:
1703                         case IPV6_2292HOPLIMIT:
1704                         case IPV6_2292HOPOPTS:
1705                         case IPV6_2292DSTOPTS:
1706                         case IPV6_2292RTHDR:
1707                                 /* RFC 2292 */
1708                                 if (optlen != sizeof(int)) {
1709                                         error = EINVAL;
1710                                         break;
1711                                 }
1712                                 error = sooptcopyin(sopt, &optval,
1713                                         sizeof optval, sizeof optval);
1714                                 if (error)
1715                                         break;
1716                                 switch (optname) {
1717                                 case IPV6_2292PKTINFO:
1718                                         OPTSET2292(IN6P_PKTINFO);
1719                                         break;
1720                                 case IPV6_2292HOPLIMIT:
1721                                         OPTSET2292(IN6P_HOPLIMIT);
1722                                         break;
1723                                 case IPV6_2292HOPOPTS:
1724                                         /*
1725                                          * Check super-user privilege.
1726                                          * See comments for IPV6_RECVHOPOPTS.
1727                                          */
1728                                         if (td != NULL) {
1729                                                 error = priv_check(td,
1730                                                     PRIV_NETINET_SETHDROPTS);
1731                                                 if (error)
1732                                                         return (error);
1733                                         }
1734                                         OPTSET2292(IN6P_HOPOPTS);
1735                                         break;
1736                                 case IPV6_2292DSTOPTS:
1737                                         if (td != NULL) {
1738                                                 error = priv_check(td,
1739                                                     PRIV_NETINET_SETHDROPTS);
1740                                                 if (error)
1741                                                         return (error);
1742                                         }
1743                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1744                                         break;
1745                                 case IPV6_2292RTHDR:
1746                                         OPTSET2292(IN6P_RTHDR);
1747                                         break;
1748                                 }
1749                                 break;
1750                         case IPV6_PKTINFO:
1751                         case IPV6_HOPOPTS:
1752                         case IPV6_RTHDR:
1753                         case IPV6_DSTOPTS:
1754                         case IPV6_RTHDRDSTOPTS:
1755                         case IPV6_NEXTHOP:
1756                         {
1757                                 /* new advanced API (RFC3542) */
1758                                 u_char *optbuf;
1759                                 u_char optbuf_storage[MCLBYTES];
1760                                 int optlen;
1761                                 struct ip6_pktopts **optp;
1762
1763                                 /* cannot mix with RFC2292 */
1764                                 if (OPTBIT(IN6P_RFC2292)) {
1765                                         error = EINVAL;
1766                                         break;
1767                                 }
1768
1769                                 /*
1770                                  * We only ensure valsize is not too large
1771                                  * here.  Further validation will be done
1772                                  * later.
1773                                  */
1774                                 error = sooptcopyin(sopt, optbuf_storage,
1775                                     sizeof(optbuf_storage), 0);
1776                                 if (error)
1777                                         break;
1778                                 optlen = sopt->sopt_valsize;
1779                                 optbuf = optbuf_storage;
1780                                 optp = &in6p->in6p_outputopts;
1781                                 error = ip6_pcbopt(optname, optbuf, optlen,
1782                                     optp, (td != NULL) ? td->td_ucred : NULL,
1783                                     uproto);
1784                                 break;
1785                         }
1786 #undef OPTSET
1787
1788                         case IPV6_MULTICAST_IF:
1789                         case IPV6_MULTICAST_HOPS:
1790                         case IPV6_MULTICAST_LOOP:
1791                         case IPV6_JOIN_GROUP:
1792                         case IPV6_LEAVE_GROUP:
1793                         case IPV6_MSFILTER:
1794                         case MCAST_BLOCK_SOURCE:
1795                         case MCAST_UNBLOCK_SOURCE:
1796                         case MCAST_JOIN_GROUP:
1797                         case MCAST_LEAVE_GROUP:
1798                         case MCAST_JOIN_SOURCE_GROUP:
1799                         case MCAST_LEAVE_SOURCE_GROUP:
1800                                 error = ip6_setmoptions(in6p, sopt);
1801                                 break;
1802
1803                         case IPV6_PORTRANGE:
1804                                 error = sooptcopyin(sopt, &optval,
1805                                     sizeof optval, sizeof optval);
1806                                 if (error)
1807                                         break;
1808
1809                                 switch (optval) {
1810                                 case IPV6_PORTRANGE_DEFAULT:
1811                                         in6p->inp_flags &= ~(INP_LOWPORT);
1812                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1813                                         break;
1814
1815                                 case IPV6_PORTRANGE_HIGH:
1816                                         in6p->inp_flags &= ~(INP_LOWPORT);
1817                                         in6p->inp_flags |= INP_HIGHPORT;
1818                                         break;
1819
1820                                 case IPV6_PORTRANGE_LOW:
1821                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1822                                         in6p->inp_flags |= INP_LOWPORT;
1823                                         break;
1824
1825                                 default:
1826                                         error = EINVAL;
1827                                         break;
1828                                 }
1829                                 break;
1830
1831 #ifdef IPSEC
1832                         case IPV6_IPSEC_POLICY:
1833                         {
1834                                 caddr_t req;
1835                                 struct mbuf *m;
1836
1837                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1838                                         break;
1839                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1840                                         break;
1841                                 req = mtod(m, caddr_t);
1842                                 error = ipsec_set_policy(in6p, optname, req,
1843                                     m->m_len, (sopt->sopt_td != NULL) ?
1844                                     sopt->sopt_td->td_ucred : NULL);
1845                                 m_freem(m);
1846                                 break;
1847                         }
1848 #endif /* IPSEC */
1849
1850                         default:
1851                                 error = ENOPROTOOPT;
1852                                 break;
1853                         }
1854                         break;
1855
1856                 case SOPT_GET:
1857                         switch (optname) {
1858
1859                         case IPV6_2292PKTOPTIONS:
1860 #ifdef IPV6_PKTOPTIONS
1861                         case IPV6_PKTOPTIONS:
1862 #endif
1863                                 /*
1864                                  * RFC3542 (effectively) deprecated the
1865                                  * semantics of the 2292-style pktoptions.
1866                                  * Since it was not reliable in nature (i.e.,
1867                                  * applications had to expect the lack of some
1868                                  * information after all), it would make sense
1869                                  * to simplify this part by always returning
1870                                  * empty data.
1871                                  */
1872                                 sopt->sopt_valsize = 0;
1873                                 break;
1874
1875                         case IPV6_RECVHOPOPTS:
1876                         case IPV6_RECVDSTOPTS:
1877                         case IPV6_RECVRTHDRDSTOPTS:
1878                         case IPV6_UNICAST_HOPS:
1879                         case IPV6_RECVPKTINFO:
1880                         case IPV6_RECVHOPLIMIT:
1881                         case IPV6_RECVRTHDR:
1882                         case IPV6_RECVPATHMTU:
1883
1884                         case IPV6_FAITH:
1885                         case IPV6_V6ONLY:
1886                         case IPV6_PORTRANGE:
1887                         case IPV6_RECVTCLASS:
1888                         case IPV6_AUTOFLOWLABEL:
1889                         case IPV6_BINDANY:
1890                                 switch (optname) {
1891
1892                                 case IPV6_RECVHOPOPTS:
1893                                         optval = OPTBIT(IN6P_HOPOPTS);
1894                                         break;
1895
1896                                 case IPV6_RECVDSTOPTS:
1897                                         optval = OPTBIT(IN6P_DSTOPTS);
1898                                         break;
1899
1900                                 case IPV6_RECVRTHDRDSTOPTS:
1901                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1902                                         break;
1903
1904                                 case IPV6_UNICAST_HOPS:
1905                                         optval = in6p->in6p_hops;
1906                                         break;
1907
1908                                 case IPV6_RECVPKTINFO:
1909                                         optval = OPTBIT(IN6P_PKTINFO);
1910                                         break;
1911
1912                                 case IPV6_RECVHOPLIMIT:
1913                                         optval = OPTBIT(IN6P_HOPLIMIT);
1914                                         break;
1915
1916                                 case IPV6_RECVRTHDR:
1917                                         optval = OPTBIT(IN6P_RTHDR);
1918                                         break;
1919
1920                                 case IPV6_RECVPATHMTU:
1921                                         optval = OPTBIT(IN6P_MTU);
1922                                         break;
1923
1924                                 case IPV6_FAITH:
1925                                         optval = OPTBIT(INP_FAITH);
1926                                         break;
1927
1928                                 case IPV6_V6ONLY:
1929                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1930                                         break;
1931
1932                                 case IPV6_PORTRANGE:
1933                                     {
1934                                         int flags;
1935                                         flags = in6p->inp_flags;
1936                                         if (flags & INP_HIGHPORT)
1937                                                 optval = IPV6_PORTRANGE_HIGH;
1938                                         else if (flags & INP_LOWPORT)
1939                                                 optval = IPV6_PORTRANGE_LOW;
1940                                         else
1941                                                 optval = 0;
1942                                         break;
1943                                     }
1944                                 case IPV6_RECVTCLASS:
1945                                         optval = OPTBIT(IN6P_TCLASS);
1946                                         break;
1947
1948                                 case IPV6_AUTOFLOWLABEL:
1949                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1950                                         break;
1951
1952                                 case IPV6_BINDANY:
1953                                         optval = OPTBIT(INP_BINDANY);
1954                                         break;
1955                                 }
1956                                 if (error)
1957                                         break;
1958                                 error = sooptcopyout(sopt, &optval,
1959                                         sizeof optval);
1960                                 break;
1961
1962                         case IPV6_PATHMTU:
1963                         {
1964                                 u_long pmtu = 0;
1965                                 struct ip6_mtuinfo mtuinfo;
1966                                 struct route_in6 sro;
1967
1968                                 bzero(&sro, sizeof(sro));
1969
1970                                 if (!(so->so_state & SS_ISCONNECTED))
1971                                         return (ENOTCONN);
1972                                 /*
1973                                  * XXX: we dot not consider the case of source
1974                                  * routing, or optional information to specify
1975                                  * the outgoing interface.
1976                                  */
1977                                 error = ip6_getpmtu(&sro, NULL, NULL,
1978                                     &in6p->in6p_faddr, &pmtu, NULL);
1979                                 if (sro.ro_rt)
1980                                         RTFREE(sro.ro_rt);
1981                                 if (error)
1982                                         break;
1983                                 if (pmtu > IPV6_MAXPACKET)
1984                                         pmtu = IPV6_MAXPACKET;
1985
1986                                 bzero(&mtuinfo, sizeof(mtuinfo));
1987                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1988                                 optdata = (void *)&mtuinfo;
1989                                 optdatalen = sizeof(mtuinfo);
1990                                 error = sooptcopyout(sopt, optdata,
1991                                     optdatalen);
1992                                 break;
1993                         }
1994
1995                         case IPV6_2292PKTINFO:
1996                         case IPV6_2292HOPLIMIT:
1997                         case IPV6_2292HOPOPTS:
1998                         case IPV6_2292RTHDR:
1999                         case IPV6_2292DSTOPTS:
2000                                 switch (optname) {
2001                                 case IPV6_2292PKTINFO:
2002                                         optval = OPTBIT(IN6P_PKTINFO);
2003                                         break;
2004                                 case IPV6_2292HOPLIMIT:
2005                                         optval = OPTBIT(IN6P_HOPLIMIT);
2006                                         break;
2007                                 case IPV6_2292HOPOPTS:
2008                                         optval = OPTBIT(IN6P_HOPOPTS);
2009                                         break;
2010                                 case IPV6_2292RTHDR:
2011                                         optval = OPTBIT(IN6P_RTHDR);
2012                                         break;
2013                                 case IPV6_2292DSTOPTS:
2014                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2015                                         break;
2016                                 }
2017                                 error = sooptcopyout(sopt, &optval,
2018                                     sizeof optval);
2019                                 break;
2020                         case IPV6_PKTINFO:
2021                         case IPV6_HOPOPTS:
2022                         case IPV6_RTHDR:
2023                         case IPV6_DSTOPTS:
2024                         case IPV6_RTHDRDSTOPTS:
2025                         case IPV6_NEXTHOP:
2026                         case IPV6_TCLASS:
2027                         case IPV6_DONTFRAG:
2028                         case IPV6_USE_MIN_MTU:
2029                         case IPV6_PREFER_TEMPADDR:
2030                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
2031                                     optname, sopt);
2032                                 break;
2033
2034                         case IPV6_MULTICAST_IF:
2035                         case IPV6_MULTICAST_HOPS:
2036                         case IPV6_MULTICAST_LOOP:
2037                         case IPV6_MSFILTER:
2038                                 error = ip6_getmoptions(in6p, sopt);
2039                                 break;
2040
2041 #ifdef IPSEC
2042                         case IPV6_IPSEC_POLICY:
2043                           {
2044                                 caddr_t req = NULL;
2045                                 size_t len = 0;
2046                                 struct mbuf *m = NULL;
2047                                 struct mbuf **mp = &m;
2048                                 size_t ovalsize = sopt->sopt_valsize;
2049                                 caddr_t oval = (caddr_t)sopt->sopt_val;
2050
2051                                 error = soopt_getm(sopt, &m); /* XXX */
2052                                 if (error != 0)
2053                                         break;
2054                                 error = soopt_mcopyin(sopt, m); /* XXX */
2055                                 if (error != 0)
2056                                         break;
2057                                 sopt->sopt_valsize = ovalsize;
2058                                 sopt->sopt_val = oval;
2059                                 if (m) {
2060                                         req = mtod(m, caddr_t);
2061                                         len = m->m_len;
2062                                 }
2063                                 error = ipsec_get_policy(in6p, req, len, mp);
2064                                 if (error == 0)
2065                                         error = soopt_mcopyout(sopt, m); /* XXX */
2066                                 if (error == 0 && m)
2067                                         m_freem(m);
2068                                 break;
2069                           }
2070 #endif /* IPSEC */
2071
2072                         default:
2073                                 error = ENOPROTOOPT;
2074                                 break;
2075                         }
2076                         break;
2077                 }
2078         }
2079         return (error);
2080 }
2081
2082 int
2083 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2084 {
2085         int error = 0, optval, optlen;
2086         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2087         struct inpcb *in6p = sotoinpcb(so);
2088         int level, op, optname;
2089
2090         level = sopt->sopt_level;
2091         op = sopt->sopt_dir;
2092         optname = sopt->sopt_name;
2093         optlen = sopt->sopt_valsize;
2094
2095         if (level != IPPROTO_IPV6) {
2096                 return (EINVAL);
2097         }
2098
2099         switch (optname) {
2100         case IPV6_CHECKSUM:
2101                 /*
2102                  * For ICMPv6 sockets, no modification allowed for checksum
2103                  * offset, permit "no change" values to help existing apps.
2104                  *
2105                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2106                  * for an ICMPv6 socket will fail."
2107                  * The current behavior does not meet RFC3542.
2108                  */
2109                 switch (op) {
2110                 case SOPT_SET:
2111                         if (optlen != sizeof(int)) {
2112                                 error = EINVAL;
2113                                 break;
2114                         }
2115                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2116                                             sizeof(optval));
2117                         if (error)
2118                                 break;
2119                         if ((optval % 2) != 0) {
2120                                 /* the API assumes even offset values */
2121                                 error = EINVAL;
2122                         } else if (so->so_proto->pr_protocol ==
2123                             IPPROTO_ICMPV6) {
2124                                 if (optval != icmp6off)
2125                                         error = EINVAL;
2126                         } else
2127                                 in6p->in6p_cksum = optval;
2128                         break;
2129
2130                 case SOPT_GET:
2131                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2132                                 optval = icmp6off;
2133                         else
2134                                 optval = in6p->in6p_cksum;
2135
2136                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2137                         break;
2138
2139                 default:
2140                         error = EINVAL;
2141                         break;
2142                 }
2143                 break;
2144
2145         default:
2146                 error = ENOPROTOOPT;
2147                 break;
2148         }
2149
2150         return (error);
2151 }
2152
2153 /*
2154  * Set up IP6 options in pcb for insertion in output packets or
2155  * specifying behavior of outgoing packets.
2156  */
2157 static int
2158 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2159     struct socket *so, struct sockopt *sopt)
2160 {
2161         struct ip6_pktopts *opt = *pktopt;
2162         int error = 0;
2163         struct thread *td = sopt->sopt_td;
2164
2165         /* turn off any old options. */
2166         if (opt) {
2167 #ifdef DIAGNOSTIC
2168                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2169                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2170                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2171                         printf("ip6_pcbopts: all specified options are cleared.\n");
2172 #endif
2173                 ip6_clearpktopts(opt, -1);
2174         } else
2175                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2176         *pktopt = NULL;
2177
2178         if (!m || m->m_len == 0) {
2179                 /*
2180                  * Only turning off any previous options, regardless of
2181                  * whether the opt is just created or given.
2182                  */
2183                 free(opt, M_IP6OPT);
2184                 return (0);
2185         }
2186
2187         /*  set options specified by user. */
2188         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2189             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2190                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2191                 free(opt, M_IP6OPT);
2192                 return (error);
2193         }
2194         *pktopt = opt;
2195         return (0);
2196 }
2197
2198 /*
2199  * initialize ip6_pktopts.  beware that there are non-zero default values in
2200  * the struct.
2201  */
2202 void
2203 ip6_initpktopts(struct ip6_pktopts *opt)
2204 {
2205
2206         bzero(opt, sizeof(*opt));
2207         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2208         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2209         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2210         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2211 }
2212
2213 static int
2214 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2215     struct ucred *cred, int uproto)
2216 {
2217         struct ip6_pktopts *opt;
2218
2219         if (*pktopt == NULL) {
2220                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2221                     M_WAITOK);
2222                 ip6_initpktopts(*pktopt);
2223         }
2224         opt = *pktopt;
2225
2226         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2227 }
2228
2229 static int
2230 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2231 {
2232         void *optdata = NULL;
2233         int optdatalen = 0;
2234         struct ip6_ext *ip6e;
2235         int error = 0;
2236         struct in6_pktinfo null_pktinfo;
2237         int deftclass = 0, on;
2238         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2239         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2240
2241         switch (optname) {
2242         case IPV6_PKTINFO:
2243                 if (pktopt && pktopt->ip6po_pktinfo)
2244                         optdata = (void *)pktopt->ip6po_pktinfo;
2245                 else {
2246                         /* XXX: we don't have to do this every time... */
2247                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2248                         optdata = (void *)&null_pktinfo;
2249                 }
2250                 optdatalen = sizeof(struct in6_pktinfo);
2251                 break;
2252         case IPV6_TCLASS:
2253                 if (pktopt && pktopt->ip6po_tclass >= 0)
2254                         optdata = (void *)&pktopt->ip6po_tclass;
2255                 else
2256                         optdata = (void *)&deftclass;
2257                 optdatalen = sizeof(int);
2258                 break;
2259         case IPV6_HOPOPTS:
2260                 if (pktopt && pktopt->ip6po_hbh) {
2261                         optdata = (void *)pktopt->ip6po_hbh;
2262                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2263                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2264                 }
2265                 break;
2266         case IPV6_RTHDR:
2267                 if (pktopt && pktopt->ip6po_rthdr) {
2268                         optdata = (void *)pktopt->ip6po_rthdr;
2269                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2270                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2271                 }
2272                 break;
2273         case IPV6_RTHDRDSTOPTS:
2274                 if (pktopt && pktopt->ip6po_dest1) {
2275                         optdata = (void *)pktopt->ip6po_dest1;
2276                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2277                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2278                 }
2279                 break;
2280         case IPV6_DSTOPTS:
2281                 if (pktopt && pktopt->ip6po_dest2) {
2282                         optdata = (void *)pktopt->ip6po_dest2;
2283                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2284                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2285                 }
2286                 break;
2287         case IPV6_NEXTHOP:
2288                 if (pktopt && pktopt->ip6po_nexthop) {
2289                         optdata = (void *)pktopt->ip6po_nexthop;
2290                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2291                 }
2292                 break;
2293         case IPV6_USE_MIN_MTU:
2294                 if (pktopt)
2295                         optdata = (void *)&pktopt->ip6po_minmtu;
2296                 else
2297                         optdata = (void *)&defminmtu;
2298                 optdatalen = sizeof(int);
2299                 break;
2300         case IPV6_DONTFRAG:
2301                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2302                         on = 1;
2303                 else
2304                         on = 0;
2305                 optdata = (void *)&on;
2306                 optdatalen = sizeof(on);
2307                 break;
2308         case IPV6_PREFER_TEMPADDR:
2309                 if (pktopt)
2310                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2311                 else
2312                         optdata = (void *)&defpreftemp;
2313                 optdatalen = sizeof(int);
2314                 break;
2315         default:                /* should not happen */
2316 #ifdef DIAGNOSTIC
2317                 panic("ip6_getpcbopt: unexpected option\n");
2318 #endif
2319                 return (ENOPROTOOPT);
2320         }
2321
2322         error = sooptcopyout(sopt, optdata, optdatalen);
2323
2324         return (error);
2325 }
2326
2327 void
2328 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2329 {
2330         if (pktopt == NULL)
2331                 return;
2332
2333         if (optname == -1 || optname == IPV6_PKTINFO) {
2334                 if (pktopt->ip6po_pktinfo)
2335                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2336                 pktopt->ip6po_pktinfo = NULL;
2337         }
2338         if (optname == -1 || optname == IPV6_HOPLIMIT)
2339                 pktopt->ip6po_hlim = -1;
2340         if (optname == -1 || optname == IPV6_TCLASS)
2341                 pktopt->ip6po_tclass = -1;
2342         if (optname == -1 || optname == IPV6_NEXTHOP) {
2343                 if (pktopt->ip6po_nextroute.ro_rt) {
2344                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2345                         pktopt->ip6po_nextroute.ro_rt = NULL;
2346                 }
2347                 if (pktopt->ip6po_nexthop)
2348                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2349                 pktopt->ip6po_nexthop = NULL;
2350         }
2351         if (optname == -1 || optname == IPV6_HOPOPTS) {
2352                 if (pktopt->ip6po_hbh)
2353                         free(pktopt->ip6po_hbh, M_IP6OPT);
2354                 pktopt->ip6po_hbh = NULL;
2355         }
2356         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2357                 if (pktopt->ip6po_dest1)
2358                         free(pktopt->ip6po_dest1, M_IP6OPT);
2359                 pktopt->ip6po_dest1 = NULL;
2360         }
2361         if (optname == -1 || optname == IPV6_RTHDR) {
2362                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2363                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2364                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2365                 if (pktopt->ip6po_route.ro_rt) {
2366                         RTFREE(pktopt->ip6po_route.ro_rt);
2367                         pktopt->ip6po_route.ro_rt = NULL;
2368                 }
2369         }
2370         if (optname == -1 || optname == IPV6_DSTOPTS) {
2371                 if (pktopt->ip6po_dest2)
2372                         free(pktopt->ip6po_dest2, M_IP6OPT);
2373                 pktopt->ip6po_dest2 = NULL;
2374         }
2375 }
2376
2377 #define PKTOPT_EXTHDRCPY(type) \
2378 do {\
2379         if (src->type) {\
2380                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2381                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2382                 if (dst->type == NULL && canwait == M_NOWAIT)\
2383                         goto bad;\
2384                 bcopy(src->type, dst->type, hlen);\
2385         }\
2386 } while (/*CONSTCOND*/ 0)
2387
2388 static int
2389 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2390 {
2391         if (dst == NULL || src == NULL)  {
2392                 printf("ip6_clearpktopts: invalid argument\n");
2393                 return (EINVAL);
2394         }
2395
2396         dst->ip6po_hlim = src->ip6po_hlim;
2397         dst->ip6po_tclass = src->ip6po_tclass;
2398         dst->ip6po_flags = src->ip6po_flags;
2399         dst->ip6po_minmtu = src->ip6po_minmtu;
2400         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2401         if (src->ip6po_pktinfo) {
2402                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2403                     M_IP6OPT, canwait);
2404                 if (dst->ip6po_pktinfo == NULL)
2405                         goto bad;
2406                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2407         }
2408         if (src->ip6po_nexthop) {
2409                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2410                     M_IP6OPT, canwait);
2411                 if (dst->ip6po_nexthop == NULL)
2412                         goto bad;
2413                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2414                     src->ip6po_nexthop->sa_len);
2415         }
2416         PKTOPT_EXTHDRCPY(ip6po_hbh);
2417         PKTOPT_EXTHDRCPY(ip6po_dest1);
2418         PKTOPT_EXTHDRCPY(ip6po_dest2);
2419         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2420         return (0);
2421
2422   bad:
2423         ip6_clearpktopts(dst, -1);
2424         return (ENOBUFS);
2425 }
2426 #undef PKTOPT_EXTHDRCPY
2427
2428 struct ip6_pktopts *
2429 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2430 {
2431         int error;
2432         struct ip6_pktopts *dst;
2433
2434         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2435         if (dst == NULL)
2436                 return (NULL);
2437         ip6_initpktopts(dst);
2438
2439         if ((error = copypktopts(dst, src, canwait)) != 0) {
2440                 free(dst, M_IP6OPT);
2441                 return (NULL);
2442         }
2443
2444         return (dst);
2445 }
2446
2447 void
2448 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2449 {
2450         if (pktopt == NULL)
2451                 return;
2452
2453         ip6_clearpktopts(pktopt, -1);
2454
2455         free(pktopt, M_IP6OPT);
2456 }
2457
2458 /*
2459  * Set IPv6 outgoing packet options based on advanced API.
2460  */
2461 int
2462 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2463     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2464 {
2465         struct cmsghdr *cm = 0;
2466
2467         if (control == NULL || opt == NULL)
2468                 return (EINVAL);
2469
2470         ip6_initpktopts(opt);
2471         if (stickyopt) {
2472                 int error;
2473
2474                 /*
2475                  * If stickyopt is provided, make a local copy of the options
2476                  * for this particular packet, then override them by ancillary
2477                  * objects.
2478                  * XXX: copypktopts() does not copy the cached route to a next
2479                  * hop (if any).  This is not very good in terms of efficiency,
2480                  * but we can allow this since this option should be rarely
2481                  * used.
2482                  */
2483                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2484                         return (error);
2485         }
2486
2487         /*
2488          * XXX: Currently, we assume all the optional information is stored
2489          * in a single mbuf.
2490          */
2491         if (control->m_next)
2492                 return (EINVAL);
2493
2494         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2495             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2496                 int error;
2497
2498                 if (control->m_len < CMSG_LEN(0))
2499                         return (EINVAL);
2500
2501                 cm = mtod(control, struct cmsghdr *);
2502                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2503                         return (EINVAL);
2504                 if (cm->cmsg_level != IPPROTO_IPV6)
2505                         continue;
2506
2507                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2508                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2509                 if (error)
2510                         return (error);
2511         }
2512
2513         return (0);
2514 }
2515
2516 /*
2517  * Set a particular packet option, as a sticky option or an ancillary data
2518  * item.  "len" can be 0 only when it's a sticky option.
2519  * We have 4 cases of combination of "sticky" and "cmsg":
2520  * "sticky=0, cmsg=0": impossible
2521  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2522  * "sticky=1, cmsg=0": RFC3542 socket option
2523  * "sticky=1, cmsg=1": RFC2292 socket option
2524  */
2525 static int
2526 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2527     struct ucred *cred, int sticky, int cmsg, int uproto)
2528 {
2529         int minmtupolicy, preftemp;
2530         int error;
2531
2532         if (!sticky && !cmsg) {
2533 #ifdef DIAGNOSTIC
2534                 printf("ip6_setpktopt: impossible case\n");
2535 #endif
2536                 return (EINVAL);
2537         }
2538
2539         /*
2540          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2541          * not be specified in the context of RFC3542.  Conversely,
2542          * RFC3542 types should not be specified in the context of RFC2292.
2543          */
2544         if (!cmsg) {
2545                 switch (optname) {
2546                 case IPV6_2292PKTINFO:
2547                 case IPV6_2292HOPLIMIT:
2548                 case IPV6_2292NEXTHOP:
2549                 case IPV6_2292HOPOPTS:
2550                 case IPV6_2292DSTOPTS:
2551                 case IPV6_2292RTHDR:
2552                 case IPV6_2292PKTOPTIONS:
2553                         return (ENOPROTOOPT);
2554                 }
2555         }
2556         if (sticky && cmsg) {
2557                 switch (optname) {
2558                 case IPV6_PKTINFO:
2559                 case IPV6_HOPLIMIT:
2560                 case IPV6_NEXTHOP:
2561                 case IPV6_HOPOPTS:
2562                 case IPV6_DSTOPTS:
2563                 case IPV6_RTHDRDSTOPTS:
2564                 case IPV6_RTHDR:
2565                 case IPV6_USE_MIN_MTU:
2566                 case IPV6_DONTFRAG:
2567                 case IPV6_TCLASS:
2568                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2569                         return (ENOPROTOOPT);
2570                 }
2571         }
2572
2573         switch (optname) {
2574         case IPV6_2292PKTINFO:
2575         case IPV6_PKTINFO:
2576         {
2577                 struct ifnet *ifp = NULL;
2578                 struct in6_pktinfo *pktinfo;
2579
2580                 if (len != sizeof(struct in6_pktinfo))
2581                         return (EINVAL);
2582
2583                 pktinfo = (struct in6_pktinfo *)buf;
2584
2585                 /*
2586                  * An application can clear any sticky IPV6_PKTINFO option by
2587                  * doing a "regular" setsockopt with ipi6_addr being
2588                  * in6addr_any and ipi6_ifindex being zero.
2589                  * [RFC 3542, Section 6]
2590                  */
2591                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2592                     pktinfo->ipi6_ifindex == 0 &&
2593                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2594                         ip6_clearpktopts(opt, optname);
2595                         break;
2596                 }
2597
2598                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2599                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2600                         return (EINVAL);
2601                 }
2602
2603                 /* validate the interface index if specified. */
2604                 if (pktinfo->ipi6_ifindex > V_if_index ||
2605                     pktinfo->ipi6_ifindex < 0) {
2606                          return (ENXIO);
2607                 }
2608                 if (pktinfo->ipi6_ifindex) {
2609                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2610                         if (ifp == NULL)
2611                                 return (ENXIO);
2612                 }
2613
2614                 /*
2615                  * We store the address anyway, and let in6_selectsrc()
2616                  * validate the specified address.  This is because ipi6_addr
2617                  * may not have enough information about its scope zone, and
2618                  * we may need additional information (such as outgoing
2619                  * interface or the scope zone of a destination address) to
2620                  * disambiguate the scope.
2621                  * XXX: the delay of the validation may confuse the
2622                  * application when it is used as a sticky option.
2623                  */
2624                 if (opt->ip6po_pktinfo == NULL) {
2625                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2626                             M_IP6OPT, M_NOWAIT);
2627                         if (opt->ip6po_pktinfo == NULL)
2628                                 return (ENOBUFS);
2629                 }
2630                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2631                 break;
2632         }
2633
2634         case IPV6_2292HOPLIMIT:
2635         case IPV6_HOPLIMIT:
2636         {
2637                 int *hlimp;
2638
2639                 /*
2640                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2641                  * to simplify the ordering among hoplimit options.
2642                  */
2643                 if (optname == IPV6_HOPLIMIT && sticky)
2644                         return (ENOPROTOOPT);
2645
2646                 if (len != sizeof(int))
2647                         return (EINVAL);
2648                 hlimp = (int *)buf;
2649                 if (*hlimp < -1 || *hlimp > 255)
2650                         return (EINVAL);
2651
2652                 opt->ip6po_hlim = *hlimp;
2653                 break;
2654         }
2655
2656         case IPV6_TCLASS:
2657         {
2658                 int tclass;
2659
2660                 if (len != sizeof(int))
2661                         return (EINVAL);
2662                 tclass = *(int *)buf;
2663                 if (tclass < -1 || tclass > 255)
2664                         return (EINVAL);
2665
2666                 opt->ip6po_tclass = tclass;
2667                 break;
2668         }
2669
2670         case IPV6_2292NEXTHOP:
2671         case IPV6_NEXTHOP:
2672                 if (cred != NULL) {
2673                         error = priv_check_cred(cred,
2674                             PRIV_NETINET_SETHDROPTS, 0);
2675                         if (error)
2676                                 return (error);
2677                 }
2678
2679                 if (len == 0) { /* just remove the option */
2680                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2681                         break;
2682                 }
2683
2684                 /* check if cmsg_len is large enough for sa_len */
2685                 if (len < sizeof(struct sockaddr) || len < *buf)
2686                         return (EINVAL);
2687
2688                 switch (((struct sockaddr *)buf)->sa_family) {
2689                 case AF_INET6:
2690                 {
2691                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2692                         int error;
2693
2694                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2695                                 return (EINVAL);
2696
2697                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2698                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2699                                 return (EINVAL);
2700                         }
2701                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2702                             != 0) {
2703                                 return (error);
2704                         }
2705                         break;
2706                 }
2707                 case AF_LINK:   /* should eventually be supported */
2708                 default:
2709                         return (EAFNOSUPPORT);
2710                 }
2711
2712                 /* turn off the previous option, then set the new option. */
2713                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2714                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2715                 if (opt->ip6po_nexthop == NULL)
2716                         return (ENOBUFS);
2717                 bcopy(buf, opt->ip6po_nexthop, *buf);
2718                 break;
2719
2720         case IPV6_2292HOPOPTS:
2721         case IPV6_HOPOPTS:
2722         {
2723                 struct ip6_hbh *hbh;
2724                 int hbhlen;
2725
2726                 /*
2727                  * XXX: We don't allow a non-privileged user to set ANY HbH
2728                  * options, since per-option restriction has too much
2729                  * overhead.
2730                  */
2731                 if (cred != NULL) {
2732                         error = priv_check_cred(cred,
2733                             PRIV_NETINET_SETHDROPTS, 0);
2734                         if (error)
2735                                 return (error);
2736                 }
2737
2738                 if (len == 0) {
2739                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2740                         break;  /* just remove the option */
2741                 }
2742
2743                 /* message length validation */
2744                 if (len < sizeof(struct ip6_hbh))
2745                         return (EINVAL);
2746                 hbh = (struct ip6_hbh *)buf;
2747                 hbhlen = (hbh->ip6h_len + 1) << 3;
2748                 if (len != hbhlen)
2749                         return (EINVAL);
2750
2751                 /* turn off the previous option, then set the new option. */
2752                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2753                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2754                 if (opt->ip6po_hbh == NULL)
2755                         return (ENOBUFS);
2756                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2757
2758                 break;
2759         }
2760
2761         case IPV6_2292DSTOPTS:
2762         case IPV6_DSTOPTS:
2763         case IPV6_RTHDRDSTOPTS:
2764         {
2765                 struct ip6_dest *dest, **newdest = NULL;
2766                 int destlen;
2767
2768                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2769                         error = priv_check_cred(cred,
2770                             PRIV_NETINET_SETHDROPTS, 0);
2771                         if (error)
2772                                 return (error);
2773                 }
2774
2775                 if (len == 0) {
2776                         ip6_clearpktopts(opt, optname);
2777                         break;  /* just remove the option */
2778                 }
2779
2780                 /* message length validation */
2781                 if (len < sizeof(struct ip6_dest))
2782                         return (EINVAL);
2783                 dest = (struct ip6_dest *)buf;
2784                 destlen = (dest->ip6d_len + 1) << 3;
2785                 if (len != destlen)
2786                         return (EINVAL);
2787
2788                 /*
2789                  * Determine the position that the destination options header
2790                  * should be inserted; before or after the routing header.
2791                  */
2792                 switch (optname) {
2793                 case IPV6_2292DSTOPTS:
2794                         /*
2795                          * The old advacned API is ambiguous on this point.
2796                          * Our approach is to determine the position based
2797                          * according to the existence of a routing header.
2798                          * Note, however, that this depends on the order of the
2799                          * extension headers in the ancillary data; the 1st
2800                          * part of the destination options header must appear
2801                          * before the routing header in the ancillary data,
2802                          * too.
2803                          * RFC3542 solved the ambiguity by introducing
2804                          * separate ancillary data or option types.
2805                          */
2806                         if (opt->ip6po_rthdr == NULL)
2807                                 newdest = &opt->ip6po_dest1;
2808                         else
2809                                 newdest = &opt->ip6po_dest2;
2810                         break;
2811                 case IPV6_RTHDRDSTOPTS:
2812                         newdest = &opt->ip6po_dest1;
2813                         break;
2814                 case IPV6_DSTOPTS:
2815                         newdest = &opt->ip6po_dest2;
2816                         break;
2817                 }
2818
2819                 /* turn off the previous option, then set the new option. */
2820                 ip6_clearpktopts(opt, optname);
2821                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2822                 if (*newdest == NULL)
2823                         return (ENOBUFS);
2824                 bcopy(dest, *newdest, destlen);
2825
2826                 break;
2827         }
2828
2829         case IPV6_2292RTHDR:
2830         case IPV6_RTHDR:
2831         {
2832                 struct ip6_rthdr *rth;
2833                 int rthlen;
2834
2835                 if (len == 0) {
2836                         ip6_clearpktopts(opt, IPV6_RTHDR);
2837                         break;  /* just remove the option */
2838                 }
2839
2840                 /* message length validation */
2841                 if (len < sizeof(struct ip6_rthdr))
2842                         return (EINVAL);
2843                 rth = (struct ip6_rthdr *)buf;
2844                 rthlen = (rth->ip6r_len + 1) << 3;
2845                 if (len != rthlen)
2846                         return (EINVAL);
2847
2848                 switch (rth->ip6r_type) {
2849                 case IPV6_RTHDR_TYPE_0:
2850                         if (rth->ip6r_len == 0) /* must contain one addr */
2851                                 return (EINVAL);
2852                         if (rth->ip6r_len % 2) /* length must be even */
2853                                 return (EINVAL);
2854                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2855                                 return (EINVAL);
2856                         break;
2857                 default:
2858                         return (EINVAL);        /* not supported */
2859                 }
2860
2861                 /* turn off the previous option */
2862                 ip6_clearpktopts(opt, IPV6_RTHDR);
2863                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2864                 if (opt->ip6po_rthdr == NULL)
2865                         return (ENOBUFS);
2866                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2867
2868                 break;
2869         }
2870
2871         case IPV6_USE_MIN_MTU:
2872                 if (len != sizeof(int))
2873                         return (EINVAL);
2874                 minmtupolicy = *(int *)buf;
2875                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2876                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2877                     minmtupolicy != IP6PO_MINMTU_ALL) {
2878                         return (EINVAL);
2879                 }
2880                 opt->ip6po_minmtu = minmtupolicy;
2881                 break;
2882
2883         case IPV6_DONTFRAG:
2884                 if (len != sizeof(int))
2885                         return (EINVAL);
2886
2887                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2888                         /*
2889                          * we ignore this option for TCP sockets.
2890                          * (RFC3542 leaves this case unspecified.)
2891                          */
2892                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2893                 } else
2894                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2895                 break;
2896
2897         case IPV6_PREFER_TEMPADDR:
2898                 if (len != sizeof(int))
2899                         return (EINVAL);
2900                 preftemp = *(int *)buf;
2901                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2902                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2903                     preftemp != IP6PO_TEMPADDR_PREFER) {
2904                         return (EINVAL);
2905                 }
2906                 opt->ip6po_prefer_tempaddr = preftemp;
2907                 break;
2908
2909         default:
2910                 return (ENOPROTOOPT);
2911         } /* end of switch */
2912
2913         return (0);
2914 }
2915
2916 /*
2917  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2918  * packet to the input queue of a specified interface.  Note that this
2919  * calls the output routine of the loopback "driver", but with an interface
2920  * pointer that might NOT be &loif -- easier than replicating that code here.
2921  */
2922 void
2923 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2924 {
2925         struct mbuf *copym;
2926         struct ip6_hdr *ip6;
2927
2928         copym = m_copy(m, 0, M_COPYALL);
2929         if (copym == NULL)
2930                 return;
2931
2932         /*
2933          * Make sure to deep-copy IPv6 header portion in case the data
2934          * is in an mbuf cluster, so that we can safely override the IPv6
2935          * header portion later.
2936          */
2937         if ((copym->m_flags & M_EXT) != 0 ||
2938             copym->m_len < sizeof(struct ip6_hdr)) {
2939                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
2940                 if (copym == NULL)
2941                         return;
2942         }
2943
2944 #ifdef DIAGNOSTIC
2945         if (copym->m_len < sizeof(*ip6)) {
2946                 m_freem(copym);
2947                 return;
2948         }
2949 #endif
2950
2951         ip6 = mtod(copym, struct ip6_hdr *);
2952         /*
2953          * clear embedded scope identifiers if necessary.
2954          * in6_clearscope will touch the addresses only when necessary.
2955          */
2956         in6_clearscope(&ip6->ip6_src);
2957         in6_clearscope(&ip6->ip6_dst);
2958
2959         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
2960 }
2961
2962 /*
2963  * Chop IPv6 header off from the payload.
2964  */
2965 static int
2966 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
2967 {
2968         struct mbuf *mh;
2969         struct ip6_hdr *ip6;
2970
2971         ip6 = mtod(m, struct ip6_hdr *);
2972         if (m->m_len > sizeof(*ip6)) {
2973                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
2974                 if (mh == 0) {
2975                         m_freem(m);
2976                         return ENOBUFS;
2977                 }
2978                 M_MOVE_PKTHDR(mh, m);
2979                 MH_ALIGN(mh, sizeof(*ip6));
2980                 m->m_len -= sizeof(*ip6);
2981                 m->m_data += sizeof(*ip6);
2982                 mh->m_next = m;
2983                 m = mh;
2984                 m->m_len = sizeof(*ip6);
2985                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
2986         }
2987         exthdrs->ip6e_ip6 = m;
2988         return 0;
2989 }
2990
2991 /*
2992  * Compute IPv6 extension header length.
2993  */
2994 int
2995 ip6_optlen(struct inpcb *in6p)
2996 {
2997         int len;
2998
2999         if (!in6p->in6p_outputopts)
3000                 return 0;
3001
3002         len = 0;
3003 #define elen(x) \
3004     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3005
3006         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3007         if (in6p->in6p_outputopts->ip6po_rthdr)
3008                 /* dest1 is valid with rthdr only */
3009                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3010         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3011         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3012         return len;
3013 #undef elen
3014 }