sys/netinet6/ip6_output.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipsec.h"
  69
  70 #include <sys/param.h>
  71 #include <sys/kernel.h>
  72 #include <sys/malloc.h>
  73 #include <sys/mbuf.h>
  74 #include <sys/errno.h>
  75 #include <sys/priv.h>
  76 #include <sys/proc.h>
  77 #include <sys/protosw.h>
  78 #include <sys/socket.h>
  79 #include <sys/socketvar.h>
  80 #include <sys/syslog.h>
  81 #include <sys/ucred.h>
  82
  83 #include <net/if.h>
  84 #include <net/netisr.h>
  85 #include <net/route.h>
  86 #include <net/pfil.h>
  87 #include <net/vnet.h>
  88
  89 #include <netinet/in.h>
  90 #include <netinet/in_var.h>
  91 #include <netinet6/in6_var.h>
  92 #include <netinet/ip6.h>
  93 #include <netinet/icmp6.h>
  94 #include <netinet6/ip6_var.h>
  95 #include <netinet/in_pcb.h>
  96 #include <netinet/tcp_var.h>
  97 #include <netinet6/nd6.h>
  98
  99 #ifdef IPSEC
 100 #include <netipsec/ipsec.h>
 101 #include <netipsec/ipsec6.h>
 102 #include <netipsec/key.h>
 103 #include <netinet6/ip6_ipsec.h>
 104 #endif /* IPSEC */
 105
 106 #include <netinet6/ip6protosw.h>
 107 #include <netinet6/scope6_var.h>
 108
 109 extern int in6_mcast_loop;
 110
 111 struct ip6_exthdrs {
 112         struct mbuf *ip6e_ip6;
 113         struct mbuf *ip6e_hbh;
 114         struct mbuf *ip6e_dest1;
 115         struct mbuf *ip6e_rthdr;
 116         struct mbuf *ip6e_dest2;
 117 };
 118
 119 static int ip6_pcbopt __P((int, u_char *, int, struct ip6_pktopts **,
 120                            struct ucred *, int));
 121 static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
 122         struct socket *, struct sockopt *));
 123 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
 124 static int ip6_setpktopt __P((int, u_char *, int, struct ip6_pktopts *,
 125         struct ucred *, int, int, int));
 126
 127 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 128 static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
 129         struct ip6_frag **));
 130 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 131 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 132 static int ip6_getpmtu __P((struct route_in6 *, struct route_in6 *,
 133         struct ifnet *, struct in6_addr *, u_long *, int *));
 134 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 135
 136
 137 /*
 138  * Make an extension header from option data.  hp is the source, and
 139  * mp is the destination.
 140  */
 141 #define MAKE_EXTHDR(hp, mp)                                             \
 142     do {                                                                \
 143         if (hp) {                                                       \
 144                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 145                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 146                     ((eh)->ip6e_len + 1) << 3);                         \
 147                 if (error)                                              \
 148                         goto freehdrs;                                  \
 149         }                                                               \
 150     } while (/*CONSTCOND*/ 0)
 151
 152 /*
 153  * Form a chain of extension headers.
 154  * m is the extension header mbuf
 155  * mp is the previous mbuf in the chain
 156  * p is the next header
 157  * i is the type of option.
 158  */
 159 #define MAKE_CHAIN(m, mp, p, i)\
 160     do {\
 161         if (m) {\
 162                 if (!hdrsplit) \
 163                         panic("assumption failed: hdr not split"); \
 164                 *mtod((m), u_char *) = *(p);\
 165                 *(p) = (i);\
 166                 p = mtod((m), u_char *);\
 167                 (m)->m_next = (mp)->m_next;\
 168                 (mp)->m_next = (m);\
 169                 (mp) = (m);\
 170         }\
 171     } while (/*CONSTCOND*/ 0)
 172
 173 /*
 174  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 175  * header (with pri, len, nxt, hlim, src, dst).
 176  * This function may modify ver and hlim only.
 177  * The mbuf chain containing the packet will be freed.
 178  * The mbuf opt, if present, will not be freed.
 179  *
 180  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
 181  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 182  * which is rt_rmx.rmx_mtu.
 183  *
 184  * ifpp - XXX: just for statistics
 185  */
 186 int
 187 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 188     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 189     struct ifnet **ifpp, struct inpcb *inp)
 190 {
 191         struct ip6_hdr *ip6, *mhip6;
 192         struct ifnet *ifp, *origifp;
 193         struct mbuf *m = m0;
 194         struct mbuf *mprev = NULL;
 195         int hlen, tlen, len, off;
 196         struct route_in6 ip6route;
 197         struct rtentry *rt = NULL;
 198         struct sockaddr_in6 *dst, src_sa, dst_sa;
 199         struct in6_addr odst;
 200         int error = 0;
 201         struct in6_ifaddr *ia = NULL;
 202         u_long mtu;
 203         int alwaysfrag, dontfrag;
 204         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 205         struct ip6_exthdrs exthdrs;
 206         struct in6_addr finaldst, src0, dst0;
 207         u_int32_t zone;
 208         struct route_in6 *ro_pmtu = NULL;
 209         int hdrsplit = 0;
 210         int needipsec = 0;
 211 #ifdef IPSEC
 212         struct ipsec_output_state state;
 213         struct ip6_rthdr *rh = NULL;
 214         int needipsectun = 0;
 215         int segleft_org = 0;
 216         struct secpolicy *sp = NULL;
 217 #endif /* IPSEC */
 218
 219         ip6 = mtod(m, struct ip6_hdr *);
 220         if (ip6 == NULL) {
 221                 printf ("ip6 is NULL");
 222                 goto bad;
 223         }
 224
 225         finaldst = ip6->ip6_dst;
 226
 227         bzero(&exthdrs, sizeof(exthdrs));
 228
 229         if (opt) {
 230                 /* Hop-by-Hop options header */
 231                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 232                 /* Destination options header(1st part) */
 233                 if (opt->ip6po_rthdr) {
 234                         /*
 235                          * Destination options header(1st part)
 236                          * This only makes sense with a routing header.
 237                          * See Section 9.2 of RFC 3542.
 238                          * Disabling this part just for MIP6 convenience is
 239                          * a bad idea.  We need to think carefully about a
 240                          * way to make the advanced API coexist with MIP6
 241                          * options, which might automatically be inserted in
 242                          * the kernel.
 243                          */
 244                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 245                 }
 246                 /* Routing header */
 247                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 248                 /* Destination options header(2nd part) */
 249                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 250         }
 251
 252         /*
 253          * IPSec checking which handles several cases.
 254          * FAST IPSEC: We re-injected the packet.
 255          */
 256 #ifdef IPSEC
 257         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
 258         {
 259         case 1:                 /* Bad packet */
 260                 goto freehdrs;
 261         case -1:                /* Do IPSec */
 262                 needipsec = 1;
 263         case 0:                 /* No IPSec */
 264         default:
 265                 break;
 266         }
 267 #endif /* IPSEC */
 268
 269         /*
 270          * Calculate the total length of the extension header chain.
 271          * Keep the length of the unfragmentable part for fragmentation.
 272          */
 273         optlen = 0;
 274         if (exthdrs.ip6e_hbh)
 275                 optlen += exthdrs.ip6e_hbh->m_len;
 276         if (exthdrs.ip6e_dest1)
 277                 optlen += exthdrs.ip6e_dest1->m_len;
 278         if (exthdrs.ip6e_rthdr)
 279                 optlen += exthdrs.ip6e_rthdr->m_len;
 280         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 281
 282         /* NOTE: we don't add AH/ESP length here. do that later. */
 283         if (exthdrs.ip6e_dest2)
 284                 optlen += exthdrs.ip6e_dest2->m_len;
 285
 286         /*
 287          * If we need IPsec, or there is at least one extension header,
 288          * separate IP6 header from the payload.
 289          */
 290         if ((needipsec || optlen) && !hdrsplit) {
 291                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 292                         m = NULL;
 293                         goto freehdrs;
 294                 }
 295                 m = exthdrs.ip6e_ip6;
 296                 hdrsplit++;
 297         }
 298
 299         /* adjust pointer */
 300         ip6 = mtod(m, struct ip6_hdr *);
 301
 302         /* adjust mbuf packet header length */
 303         m->m_pkthdr.len += optlen;
 304         plen = m->m_pkthdr.len - sizeof(*ip6);
 305
 306         /* If this is a jumbo payload, insert a jumbo payload option. */
 307         if (plen > IPV6_MAXPACKET) {
 308                 if (!hdrsplit) {
 309                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 310                                 m = NULL;
 311                                 goto freehdrs;
 312                         }
 313                         m = exthdrs.ip6e_ip6;
 314                         hdrsplit++;
 315                 }
 316                 /* adjust pointer */
 317                 ip6 = mtod(m, struct ip6_hdr *);
 318                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 319                         goto freehdrs;
 320                 ip6->ip6_plen = 0;
 321         } else
 322                 ip6->ip6_plen = htons(plen);
 323
 324         /*
 325          * Concatenate headers and fill in next header fields.
 326          * Here we have, on "m"
 327          *      IPv6 payload
 328          * and we insert headers accordingly.  Finally, we should be getting:
 329          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 330          *
 331          * during the header composing process, "m" points to IPv6 header.
 332          * "mprev" points to an extension header prior to esp.
 333          */
 334         u_char *nexthdrp = &ip6->ip6_nxt;
 335         mprev = m;
 336
 337         /*
 338          * we treat dest2 specially.  this makes IPsec processing
 339          * much easier.  the goal here is to make mprev point the
 340          * mbuf prior to dest2.
 341          *
 342          * result: IPv6 dest2 payload
 343          * m and mprev will point to IPv6 header.
 344          */
 345         if (exthdrs.ip6e_dest2) {
 346                 if (!hdrsplit)
 347                         panic("assumption failed: hdr not split");
 348                 exthdrs.ip6e_dest2->m_next = m->m_next;
 349                 m->m_next = exthdrs.ip6e_dest2;
 350                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 351                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 352         }
 353
 354         /*
 355          * result: IPv6 hbh dest1 rthdr dest2 payload
 356          * m will point to IPv6 header.  mprev will point to the
 357          * extension header prior to dest2 (rthdr in the above case).
 358          */
 359         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 360         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 361                    IPPROTO_DSTOPTS);
 362         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 363                    IPPROTO_ROUTING);
 364
 365 #ifdef IPSEC
 366         if (!needipsec)
 367                 goto skip_ipsec2;
 368
 369         /*
 370          * pointers after IPsec headers are not valid any more.
 371          * other pointers need a great care too.
 372          * (IPsec routines should not mangle mbufs prior to AH/ESP)
 373          */
 374         exthdrs.ip6e_dest2 = NULL;
 375
 376         if (exthdrs.ip6e_rthdr) {
 377                 rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
 378                 segleft_org = rh->ip6r_segleft;
 379                 rh->ip6r_segleft = 0;
 380         }
 381
 382         bzero(&state, sizeof(state));
 383         state.m = m;
 384         error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
 385                                     &needipsectun);
 386         m = state.m;
 387         if (error == EJUSTRETURN) {
 388                 /*
 389                  * We had a SP with a level of 'use' and no SA. We
 390                  * will just continue to process the packet without
 391                  * IPsec processing.
 392                  */
 393                 ;
 394         } else if (error) {
 395                 /* mbuf is already reclaimed in ipsec6_output_trans. */
 396                 m = NULL;
 397                 switch (error) {
 398                 case EHOSTUNREACH:
 399                 case ENETUNREACH:
 400                 case EMSGSIZE:
 401                 case ENOBUFS:
 402                 case ENOMEM:
 403                         break;
 404                 default:
 405                         printf("[%s:%d] (ipsec): error code %d\n",
 406                             __func__, __LINE__, error);
 407                         /* FALLTHROUGH */
 408                 case ENOENT:
 409                         /* don't show these error codes to the user */
 410                         error = 0;
 411                         break;
 412                 }
 413                 goto bad;
 414         } else if (!needipsectun) {
 415                 /*
 416                  * In the FAST IPSec case we have already
 417                  * re-injected the packet and it has been freed
 418                  * by the ipsec_done() function.  So, just clean
 419                  * up after ourselves.
 420                  */
 421                 m = NULL;
 422                 goto done;
 423         }
 424         if (exthdrs.ip6e_rthdr) {
 425                 /* ah6_output doesn't modify mbuf chain */
 426                 rh->ip6r_segleft = segleft_org;
 427         }
 428 skip_ipsec2:;
 429 #endif /* IPSEC */
 430
 431         /*
 432          * If there is a routing header, discard the packet.
 433          */
 434         if (exthdrs.ip6e_rthdr) {
 435                  error = EINVAL;
 436                  goto bad;
 437         }
 438
 439         /* Source address validation */
 440         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 441             (flags & IPV6_UNSPECSRC) == 0) {
 442                 error = EOPNOTSUPP;
 443                 V_ip6stat.ip6s_badscope++;
 444                 goto bad;
 445         }
 446         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 447                 error = EOPNOTSUPP;
 448                 V_ip6stat.ip6s_badscope++;
 449                 goto bad;
 450         }
 451
 452         V_ip6stat.ip6s_localout++;
 453
 454         /*
 455          * Route packet.
 456          */
 457         if (ro == 0) {
 458                 ro = &ip6route;
 459                 bzero((caddr_t)ro, sizeof(*ro));
 460         }
 461         ro_pmtu = ro;
 462         if (opt && opt->ip6po_rthdr)
 463                 ro = &opt->ip6po_route;
 464         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 465
 466 again:
 467         /*
 468          * if specified, try to fill in the traffic class field.
 469          * do not override if a non-zero value is already set.
 470          * we check the diffserv field and the ecn field separately.
 471          */
 472         if (opt && opt->ip6po_tclass >= 0) {
 473                 int mask = 0;
 474
 475                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 476                         mask |= 0xfc;
 477                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 478                         mask |= 0x03;
 479                 if (mask != 0)
 480                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 481         }
 482
 483         /* fill in or override the hop limit field, if necessary. */
 484         if (opt && opt->ip6po_hlim != -1)
 485                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 486         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 487                 if (im6o != NULL)
 488                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 489                 else
 490                         ip6->ip6_hlim = V_ip6_defmcasthlim;
 491         }
 492
 493 #ifdef IPSEC
 494         /*
 495          * We may re-inject packets into the stack here.
 496          */
 497         if (needipsec && needipsectun) {
 498                 struct ipsec_output_state state;
 499
 500                 /*
 501                  * All the extension headers will become inaccessible
 502                  * (since they can be encrypted).
 503                  * Don't panic, we need no more updates to extension headers
 504                  * on inner IPv6 packet (since they are now encapsulated).
 505                  *
 506                  * IPv6 [ESP|AH] IPv6 [extension headers] payload
 507                  */
 508                 bzero(&exthdrs, sizeof(exthdrs));
 509                 exthdrs.ip6e_ip6 = m;
 510
 511                 bzero(&state, sizeof(state));
 512                 state.m = m;
 513                 state.ro = (struct route *)ro;
 514                 state.dst = (struct sockaddr *)dst;
 515
 516                 error = ipsec6_output_tunnel(&state, sp, flags);
 517
 518                 m = state.m;
 519                 ro = (struct route_in6 *)state.ro;
 520                 dst = (struct sockaddr_in6 *)state.dst;
 521                 if (error == EJUSTRETURN) {
 522                         /*
 523                          * We had a SP with a level of 'use' and no SA. We
 524                          * will just continue to process the packet without
 525                          * IPsec processing.
 526                          */
 527                         ;
 528                 } else if (error) {
 529                         /* mbuf is already reclaimed in ipsec6_output_tunnel. */
 530                         m0 = m = NULL;
 531                         m = NULL;
 532                         switch (error) {
 533                         case EHOSTUNREACH:
 534                         case ENETUNREACH:
 535                         case EMSGSIZE:
 536                         case ENOBUFS:
 537                         case ENOMEM:
 538                                 break;
 539                         default:
 540                                 printf("[%s:%d] (ipsec): error code %d\n",
 541                                     __func__, __LINE__, error);
 542                                 /* FALLTHROUGH */
 543                         case ENOENT:
 544                                 /* don't show these error codes to the user */
 545                                 error = 0;
 546                                 break;
 547                         }
 548                         goto bad;
 549                 } else {
 550                         /*
 551                          * In the FAST IPSec case we have already
 552                          * re-injected the packet and it has been freed
 553                          * by the ipsec_done() function.  So, just clean
 554                          * up after ourselves.
 555                          */
 556                         m = NULL;
 557                         goto done;
 558                 }
 559
 560                 exthdrs.ip6e_ip6 = m;
 561         }
 562 #endif /* IPSEC */
 563
 564         /* adjust pointer */
 565         ip6 = mtod(m, struct ip6_hdr *);
 566
 567         bzero(&dst_sa, sizeof(dst_sa));
 568         dst_sa.sin6_family = AF_INET6;
 569         dst_sa.sin6_len = sizeof(dst_sa);
 570         dst_sa.sin6_addr = ip6->ip6_dst;
 571         if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
 572             &ifp, &rt)) != 0) {
 573                 switch (error) {
 574                 case EHOSTUNREACH:
 575                         V_ip6stat.ip6s_noroute++;
 576                         break;
 577                 case EADDRNOTAVAIL:
 578                 default:
 579                         break; /* XXX statistics? */
 580                 }
 581                 if (ifp != NULL)
 582                         in6_ifstat_inc(ifp, ifs6_out_discard);
 583                 goto bad;
 584         }
 585         if (rt == NULL) {
 586                 /*
 587                  * If in6_selectroute() does not return a route entry,
 588                  * dst may not have been updated.
 589                  */
 590                 *dst = dst_sa;  /* XXX */
 591         }
 592
 593         /*
 594          * then rt (for unicast) and ifp must be non-NULL valid values.
 595          */
 596         if ((flags & IPV6_FORWARDING) == 0) {
 597                 /* XXX: the FORWARDING flag can be set for mrouting. */
 598                 in6_ifstat_inc(ifp, ifs6_out_request);
 599         }
 600         if (rt != NULL) {
 601                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 602                 rt->rt_use++;
 603         }
 604
 605
 606         /*
 607          * The outgoing interface must be in the zone of source and
 608          * destination addresses.
 609          */
 610         origifp = ifp;
 611
 612         src0 = ip6->ip6_src;
 613         if (in6_setscope(&src0, origifp, &zone))
 614                 goto badscope;
 615         bzero(&src_sa, sizeof(src_sa));
 616         src_sa.sin6_family = AF_INET6;
 617         src_sa.sin6_len = sizeof(src_sa);
 618         src_sa.sin6_addr = ip6->ip6_src;
 619         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 620                 goto badscope;
 621
 622         dst0 = ip6->ip6_dst;
 623         if (in6_setscope(&dst0, origifp, &zone))
 624                 goto badscope;
 625         /* re-initialize to be sure */
 626         bzero(&dst_sa, sizeof(dst_sa));
 627         dst_sa.sin6_family = AF_INET6;
 628         dst_sa.sin6_len = sizeof(dst_sa);
 629         dst_sa.sin6_addr = ip6->ip6_dst;
 630         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 631                 goto badscope;
 632         }
 633
 634         /* We should use ia_ifp to support the case of
 635          * sending packets to an address of our own.
 636          */
 637         if (ia != NULL && ia->ia_ifp)
 638                 ifp = ia->ia_ifp;
 639
 640         /* scope check is done. */
 641         goto routefound;
 642
 643   badscope:
 644         V_ip6stat.ip6s_badscope++;
 645         in6_ifstat_inc(origifp, ifs6_out_discard);
 646         if (error == 0)
 647                 error = EHOSTUNREACH; /* XXX */
 648         goto bad;
 649
 650   routefound:
 651         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 652                 if (opt && opt->ip6po_nextroute.ro_rt) {
 653                         /*
 654                          * The nexthop is explicitly specified by the
 655                          * application.  We assume the next hop is an IPv6
 656                          * address.
 657                          */
 658                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 659                 }
 660                 else if ((rt->rt_flags & RTF_GATEWAY))
 661                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 662         }
 663
 664         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 665                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 666         } else {
 667                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 668                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 669                 /*
 670                  * Confirm that the outgoing interface supports multicast.
 671                  */
 672                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 673                         V_ip6stat.ip6s_noroute++;
 674                         in6_ifstat_inc(ifp, ifs6_out_discard);
 675                         error = ENETUNREACH;
 676                         goto bad;
 677                 }
 678                 if ((im6o == NULL && in6_mcast_loop) ||
 679                     (im6o && im6o->im6o_multicast_loop)) {
 680                         /*
 681                          * Loop back multicast datagram if not expressly
 682                          * forbidden to do so, even if we have not joined
 683                          * the address; protocols will filter it later,
 684                          * thus deferring a hash lookup and lock acquisition
 685                          * at the expense of an m_copym().
 686                          */
 687                         ip6_mloopback(ifp, m, dst);
 688                 } else {
 689                         /*
 690                          * If we are acting as a multicast router, perform
 691                          * multicast forwarding as if the packet had just
 692                          * arrived on the interface to which we are about
 693                          * to send.  The multicast forwarding function
 694                          * recursively calls this function, using the
 695                          * IPV6_FORWARDING flag to prevent infinite recursion.
 696                          *
 697                          * Multicasts that are looped back by ip6_mloopback(),
 698                          * above, will be forwarded by the ip6_input() routine,
 699                          * if necessary.
 700                          */
 701                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 702                                 /*
 703                                  * XXX: ip6_mforward expects that rcvif is NULL
 704                                  * when it is called from the originating path.
 705                                  * However, it is not always the case, since
 706                                  * some versions of MGETHDR() does not
 707                                  * initialize the field.
 708                                  */
 709                                 m->m_pkthdr.rcvif = NULL;
 710                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 711                                         m_freem(m);
 712                                         goto done;
 713                                 }
 714                         }
 715                 }
 716                 /*
 717                  * Multicasts with a hoplimit of zero may be looped back,
 718                  * above, but must not be transmitted on a network.
 719                  * Also, multicasts addressed to the loopback interface
 720                  * are not sent -- the above call to ip6_mloopback() will
 721                  * loop back a copy if this host actually belongs to the
 722                  * destination group on the loopback interface.
 723                  */
 724                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 725                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 726                         m_freem(m);
 727                         goto done;
 728                 }
 729         }
 730
 731         /*
 732          * Fill the outgoing inteface to tell the upper layer
 733          * to increment per-interface statistics.
 734          */
 735         if (ifpp)
 736                 *ifpp = ifp;
 737
 738         /* Determine path MTU. */
 739         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
 740             &alwaysfrag)) != 0)
 741                 goto bad;
 742
 743         /*
 744          * The caller of this function may specify to use the minimum MTU
 745          * in some cases.
 746          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 747          * setting.  The logic is a bit complicated; by default, unicast
 748          * packets will follow path MTU while multicast packets will be sent at
 749          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 750          * including unicast ones will be sent at the minimum MTU.  Multicast
 751          * packets will always be sent at the minimum MTU unless
 752          * IP6PO_MINMTU_DISABLE is explicitly specified.
 753          * See RFC 3542 for more details.
 754          */
 755         if (mtu > IPV6_MMTU) {
 756                 if ((flags & IPV6_MINMTU))
 757                         mtu = IPV6_MMTU;
 758                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 759                         mtu = IPV6_MMTU;
 760                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 761                          (opt == NULL ||
 762                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 763                         mtu = IPV6_MMTU;
 764                 }
 765         }
 766
 767         /*
 768          * clear embedded scope identifiers if necessary.
 769          * in6_clearscope will touch the addresses only when necessary.
 770          */
 771         in6_clearscope(&ip6->ip6_src);
 772         in6_clearscope(&ip6->ip6_dst);
 773
 774         /*
 775          * If the outgoing packet contains a hop-by-hop options header,
 776          * it must be examined and processed even by the source node.
 777          * (RFC 2460, section 4.)
 778          */
 779         if (exthdrs.ip6e_hbh) {
 780                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 781                 u_int32_t dummy; /* XXX unused */
 782                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 783
 784 #ifdef DIAGNOSTIC
 785                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 786                         panic("ip6e_hbh is not continuous");
 787 #endif
 788                 /*
 789                  *  XXX: if we have to send an ICMPv6 error to the sender,
 790                  *       we need the M_LOOP flag since icmp6_error() expects
 791                  *       the IPv6 and the hop-by-hop options header are
 792                  *       continuous unless the flag is set.
 793                  */
 794                 m->m_flags |= M_LOOP;
 795                 m->m_pkthdr.rcvif = ifp;
 796                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 797                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 798                     &dummy, &plen) < 0) {
 799                         /* m was already freed at this point */
 800                         error = EINVAL;/* better error? */
 801                         goto done;
 802                 }
 803                 m->m_flags &= ~M_LOOP; /* XXX */
 804                 m->m_pkthdr.rcvif = NULL;
 805         }
 806
 807         /* Jump over all PFIL processing if hooks are not active. */
 808         if (!PFIL_HOOKED(&inet6_pfil_hook))
 809                 goto passout;
 810
 811         odst = ip6->ip6_dst;
 812         /* Run through list of hooks for output packets. */
 813         error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 814         if (error != 0 || m == NULL)
 815                 goto done;
 816         ip6 = mtod(m, struct ip6_hdr *);
 817
 818         /* See if destination IP address was changed by packet filter. */
 819         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 820                 m->m_flags |= M_SKIP_FIREWALL;
 821                 /* If destination is now ourself drop to ip6_input(). */
 822                 if (in6_localaddr(&ip6->ip6_dst)) {
 823                         if (m->m_pkthdr.rcvif == NULL)
 824                                 m->m_pkthdr.rcvif = V_loif;
 825                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 826                                 m->m_pkthdr.csum_flags |=
 827                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 828                                 m->m_pkthdr.csum_data = 0xffff;
 829                         }
 830                         m->m_pkthdr.csum_flags |=
 831                             CSUM_IP_CHECKED | CSUM_IP_VALID;
 832                         error = netisr_queue(NETISR_IPV6, m);
 833                         goto done;
 834                 } else
 835                         goto again;     /* Redo the routing table lookup. */
 836         }
 837
 838         /* XXX: IPFIREWALL_FORWARD */
 839
 840 passout:
 841         /*
 842          * Send the packet to the outgoing interface.
 843          * If necessary, do IPv6 fragmentation before sending.
 844          *
 845          * the logic here is rather complex:
 846          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 847          * 1-a: send as is if tlen <= path mtu
 848          * 1-b: fragment if tlen > path mtu
 849          *
 850          * 2: if user asks us not to fragment (dontfrag == 1)
 851          * 2-a: send as is if tlen <= interface mtu
 852          * 2-b: error if tlen > interface mtu
 853          *
 854          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 855          *      always fragment
 856          *
 857          * 4: if dontfrag == 1 && alwaysfrag == 1
 858          *      error, as we cannot handle this conflicting request
 859          */
 860         tlen = m->m_pkthdr.len;
 861
 862         if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
 863                 dontfrag = 1;
 864         else
 865                 dontfrag = 0;
 866         if (dontfrag && alwaysfrag) {   /* case 4 */
 867                 /* conflicting request - can't transmit */
 868                 error = EMSGSIZE;
 869                 goto bad;
 870         }
 871         if (dontfrag && tlen > IN6_LINKMTU(ifp)) {      /* case 2-b */
 872                 /*
 873                  * Even if the DONTFRAG option is specified, we cannot send the
 874                  * packet when the data length is larger than the MTU of the
 875                  * outgoing interface.
 876                  * Notify the error by sending IPV6_PATHMTU ancillary data as
 877                  * well as returning an error code (the latter is not described
 878                  * in the API spec.)
 879                  */
 880                 u_int32_t mtu32;
 881                 struct ip6ctlparam ip6cp;
 882
 883                 mtu32 = (u_int32_t)mtu;
 884                 bzero(&ip6cp, sizeof(ip6cp));
 885                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
 886                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
 887                     (void *)&ip6cp);
 888
 889                 error = EMSGSIZE;
 890                 goto bad;
 891         }
 892
 893         /*
 894          * transmit packet without fragmentation
 895          */
 896         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 897                 struct in6_ifaddr *ia6;
 898
 899                 ip6 = mtod(m, struct ip6_hdr *);
 900                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 901                 if (ia6) {
 902                         /* Record statistics for this interface address. */
 903                         ia6->ia_ifa.if_opackets++;
 904                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
 905                         ifa_free(&ia6->ia_ifa);
 906                 }
 907                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
 908                 goto done;
 909         }
 910
 911         /*
 912          * try to fragment the packet.  case 1-b and 3
 913          */
 914         if (mtu < IPV6_MMTU) {
 915                 /* path MTU cannot be less than IPV6_MMTU */
 916                 error = EMSGSIZE;
 917                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 918                 goto bad;
 919         } else if (ip6->ip6_plen == 0) {
 920                 /* jumbo payload cannot be fragmented */
 921                 error = EMSGSIZE;
 922                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 923                 goto bad;
 924         } else {
 925                 struct mbuf **mnext, *m_frgpart;
 926                 struct ip6_frag *ip6f;
 927                 u_int32_t id = htonl(ip6_randomid());
 928                 u_char nextproto;
 929
 930                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
 931
 932                 /*
 933                  * Too large for the destination or interface;
 934                  * fragment if possible.
 935                  * Must be able to put at least 8 bytes per fragment.
 936                  */
 937                 hlen = unfragpartlen;
 938                 if (mtu > IPV6_MAXPACKET)
 939                         mtu = IPV6_MAXPACKET;
 940
 941                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 942                 if (len < 8) {
 943                         error = EMSGSIZE;
 944                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
 945                         goto bad;
 946                 }
 947
 948                 /*
 949                  * Verify that we have any chance at all of being able to queue
 950                  *      the packet or packet fragments
 951                  */
 952                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
 953                     < tlen  /* - hlen */)) {
 954                         error = ENOBUFS;
 955                         V_ip6stat.ip6s_odropped++;
 956                         goto bad;
 957                 }
 958
 959                 mnext = &m->m_nextpkt;
 960
 961                 /*
 962                  * Change the next header field of the last header in the
 963                  * unfragmentable part.
 964                  */
 965                 if (exthdrs.ip6e_rthdr) {
 966                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
 967                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
 968                 } else if (exthdrs.ip6e_dest1) {
 969                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
 970                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
 971                 } else if (exthdrs.ip6e_hbh) {
 972                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
 973                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
 974                 } else {
 975                         nextproto = ip6->ip6_nxt;
 976                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
 977                 }
 978
 979                 /*
 980                  * Loop through length of segment after first fragment,
 981                  * make new header and copy data of each part and link onto
 982                  * chain.
 983                  */
 984                 m0 = m;
 985                 for (off = hlen; off < tlen; off += len) {
 986                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
 987                         if (!m) {
 988                                 error = ENOBUFS;
 989                                 V_ip6stat.ip6s_odropped++;
 990                                 goto sendorfree;
 991                         }
 992                         m->m_pkthdr.rcvif = NULL;
 993                         m->m_flags = m0->m_flags & M_COPYFLAGS;
 994                         *mnext = m;
 995                         mnext = &m->m_nextpkt;
 996                         m->m_data += max_linkhdr;
 997                         mhip6 = mtod(m, struct ip6_hdr *);
 998                         *mhip6 = *ip6;
 999                         m->m_len = sizeof(*mhip6);
1000                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1001                         if (error) {
1002                                 V_ip6stat.ip6s_odropped++;
1003                                 goto sendorfree;
1004                         }
1005                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1006                         if (off + len >= tlen)
1007                                 len = tlen - off;
1008                         else
1009                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1010                         mhip6->ip6_plen = htons((u_short)(len + hlen +
1011                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1012                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1013                                 error = ENOBUFS;
1014                                 V_ip6stat.ip6s_odropped++;
1015                                 goto sendorfree;
1016                         }
1017                         m_cat(m, m_frgpart);
1018                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1019                         m->m_pkthdr.rcvif = NULL;
1020                         ip6f->ip6f_reserved = 0;
1021                         ip6f->ip6f_ident = id;
1022                         ip6f->ip6f_nxt = nextproto;
1023                         V_ip6stat.ip6s_ofragments++;
1024                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1025                 }
1026
1027                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1028         }
1029
1030         /*
1031          * Remove leading garbages.
1032          */
1033 sendorfree:
1034         m = m0->m_nextpkt;
1035         m0->m_nextpkt = 0;
1036         m_freem(m0);
1037         for (m0 = m; m; m = m0) {
1038                 m0 = m->m_nextpkt;
1039                 m->m_nextpkt = 0;
1040                 if (error == 0) {
1041                         /* Record statistics for this interface address. */
1042                         if (ia) {
1043                                 ia->ia_ifa.if_opackets++;
1044                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1045                         }
1046                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1047                 } else
1048                         m_freem(m);
1049         }
1050
1051         if (error == 0)
1052                 V_ip6stat.ip6s_fragmented++;
1053
1054 done:
1055         if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
1056                 RTFREE(ro->ro_rt);
1057         } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
1058                 RTFREE(ro_pmtu->ro_rt);
1059         }
1060 #ifdef IPSEC
1061         if (sp != NULL)
1062                 KEY_FREESP(&sp);
1063 #endif
1064
1065         return (error);
1066
1067 freehdrs:
1068         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1069         m_freem(exthdrs.ip6e_dest1);
1070         m_freem(exthdrs.ip6e_rthdr);
1071         m_freem(exthdrs.ip6e_dest2);
1072         /* FALLTHROUGH */
1073 bad:
1074         if (m)
1075                 m_freem(m);
1076         goto done;
1077 }
1078
1079 static int
1080 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1081 {
1082         struct mbuf *m;
1083
1084         if (hlen > MCLBYTES)
1085                 return (ENOBUFS); /* XXX */
1086
1087         MGET(m, M_DONTWAIT, MT_DATA);
1088         if (!m)
1089                 return (ENOBUFS);
1090
1091         if (hlen > MLEN) {
1092                 MCLGET(m, M_DONTWAIT);
1093                 if ((m->m_flags & M_EXT) == 0) {
1094                         m_free(m);
1095                         return (ENOBUFS);
1096                 }
1097         }
1098         m->m_len = hlen;
1099         if (hdr)
1100                 bcopy(hdr, mtod(m, caddr_t), hlen);
1101
1102         *mp = m;
1103         return (0);
1104 }
1105
1106 /*
1107  * Insert jumbo payload option.
1108  */
1109 static int
1110 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1111 {
1112         struct mbuf *mopt;
1113         u_char *optbuf;
1114         u_int32_t v;
1115
1116 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1117
1118         /*
1119          * If there is no hop-by-hop options header, allocate new one.
1120          * If there is one but it doesn't have enough space to store the
1121          * jumbo payload option, allocate a cluster to store the whole options.
1122          * Otherwise, use it to store the options.
1123          */
1124         if (exthdrs->ip6e_hbh == 0) {
1125                 MGET(mopt, M_DONTWAIT, MT_DATA);
1126                 if (mopt == 0)
1127                         return (ENOBUFS);
1128                 mopt->m_len = JUMBOOPTLEN;
1129                 optbuf = mtod(mopt, u_char *);
1130                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1131                 exthdrs->ip6e_hbh = mopt;
1132         } else {
1133                 struct ip6_hbh *hbh;
1134
1135                 mopt = exthdrs->ip6e_hbh;
1136                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1137                         /*
1138                          * XXX assumption:
1139                          * - exthdrs->ip6e_hbh is not referenced from places
1140                          *   other than exthdrs.
1141                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1142                          */
1143                         int oldoptlen = mopt->m_len;
1144                         struct mbuf *n;
1145
1146                         /*
1147                          * XXX: give up if the whole (new) hbh header does
1148                          * not fit even in an mbuf cluster.
1149                          */
1150                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1151                                 return (ENOBUFS);
1152
1153                         /*
1154                          * As a consequence, we must always prepare a cluster
1155                          * at this point.
1156                          */
1157                         MGET(n, M_DONTWAIT, MT_DATA);
1158                         if (n) {
1159                                 MCLGET(n, M_DONTWAIT);
1160                                 if ((n->m_flags & M_EXT) == 0) {
1161                                         m_freem(n);
1162                                         n = NULL;
1163                                 }
1164                         }
1165                         if (!n)
1166                                 return (ENOBUFS);
1167                         n->m_len = oldoptlen + JUMBOOPTLEN;
1168                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1169                             oldoptlen);
1170                         optbuf = mtod(n, caddr_t) + oldoptlen;
1171                         m_freem(mopt);
1172                         mopt = exthdrs->ip6e_hbh = n;
1173                 } else {
1174                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1175                         mopt->m_len += JUMBOOPTLEN;
1176                 }
1177                 optbuf[0] = IP6OPT_PADN;
1178                 optbuf[1] = 1;
1179
1180                 /*
1181                  * Adjust the header length according to the pad and
1182                  * the jumbo payload option.
1183                  */
1184                 hbh = mtod(mopt, struct ip6_hbh *);
1185                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1186         }
1187
1188         /* fill in the option. */
1189         optbuf[2] = IP6OPT_JUMBO;
1190         optbuf[3] = 4;
1191         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1192         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1193
1194         /* finally, adjust the packet header length */
1195         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1196
1197         return (0);
1198 #undef JUMBOOPTLEN
1199 }
1200
1201 /*
1202  * Insert fragment header and copy unfragmentable header portions.
1203  */
1204 static int
1205 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1206     struct ip6_frag **frghdrp)
1207 {
1208         struct mbuf *n, *mlast;
1209
1210         if (hlen > sizeof(struct ip6_hdr)) {
1211                 n = m_copym(m0, sizeof(struct ip6_hdr),
1212                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
1213                 if (n == 0)
1214                         return (ENOBUFS);
1215                 m->m_next = n;
1216         } else
1217                 n = m;
1218
1219         /* Search for the last mbuf of unfragmentable part. */
1220         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1221                 ;
1222
1223         if ((mlast->m_flags & M_EXT) == 0 &&
1224             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1225                 /* use the trailing space of the last mbuf for the fragment hdr */
1226                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1227                     mlast->m_len);
1228                 mlast->m_len += sizeof(struct ip6_frag);
1229                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1230         } else {
1231                 /* allocate a new mbuf for the fragment header */
1232                 struct mbuf *mfrg;
1233
1234                 MGET(mfrg, M_DONTWAIT, MT_DATA);
1235                 if (mfrg == 0)
1236                         return (ENOBUFS);
1237                 mfrg->m_len = sizeof(struct ip6_frag);
1238                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1239                 mlast->m_next = mfrg;
1240         }
1241
1242         return (0);
1243 }
1244
1245 static int
1246 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1247     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1248     int *alwaysfragp)
1249 {
1250         u_int32_t mtu = 0;
1251         int alwaysfrag = 0;
1252         int error = 0;
1253
1254         if (ro_pmtu != ro) {
1255                 /* The first hop and the final destination may differ. */
1256                 struct sockaddr_in6 *sa6_dst =
1257                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1258                 if (ro_pmtu->ro_rt &&
1259                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1260                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1261                         RTFREE(ro_pmtu->ro_rt);
1262                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
1263                 }
1264                 if (ro_pmtu->ro_rt == NULL) {
1265                         bzero(sa6_dst, sizeof(*sa6_dst));
1266                         sa6_dst->sin6_family = AF_INET6;
1267                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1268                         sa6_dst->sin6_addr = *dst;
1269
1270                         rtalloc((struct route *)ro_pmtu);
1271                 }
1272         }
1273         if (ro_pmtu->ro_rt) {
1274                 u_int32_t ifmtu;
1275                 struct in_conninfo inc;
1276
1277                 bzero(&inc, sizeof(inc));
1278                 inc.inc_flags |= INC_ISIPV6;
1279                 inc.inc6_faddr = *dst;
1280
1281                 if (ifp == NULL)
1282                         ifp = ro_pmtu->ro_rt->rt_ifp;
1283                 ifmtu = IN6_LINKMTU(ifp);
1284                 mtu = tcp_hc_getmtu(&inc);
1285                 if (mtu)
1286                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
1287                 else
1288                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1289                 if (mtu == 0)
1290                         mtu = ifmtu;
1291                 else if (mtu < IPV6_MMTU) {
1292                         /*
1293                          * RFC2460 section 5, last paragraph:
1294                          * if we record ICMPv6 too big message with
1295                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1296                          * or smaller, with framgent header attached.
1297                          * (fragment header is needed regardless from the
1298                          * packet size, for translators to identify packets)
1299                          */
1300                         alwaysfrag = 1;
1301                         mtu = IPV6_MMTU;
1302                 } else if (mtu > ifmtu) {
1303                         /*
1304                          * The MTU on the route is larger than the MTU on
1305                          * the interface!  This shouldn't happen, unless the
1306                          * MTU of the interface has been changed after the
1307                          * interface was brought up.  Change the MTU in the
1308                          * route to match the interface MTU (as long as the
1309                          * field isn't locked).
1310                          */
1311                         mtu = ifmtu;
1312                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1313                 }
1314         } else if (ifp) {
1315                 mtu = IN6_LINKMTU(ifp);
1316         } else
1317                 error = EHOSTUNREACH; /* XXX */
1318
1319         *mtup = mtu;
1320         if (alwaysfragp)
1321                 *alwaysfragp = alwaysfrag;
1322         return (error);
1323 }
1324
1325 /*
1326  * IP6 socket option processing.
1327  */
1328 int
1329 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1330 {
1331         int optdatalen, uproto;
1332         void *optdata;
1333         struct inpcb *in6p = sotoinpcb(so);
1334         int error, optval;
1335         int level, op, optname;
1336         int optlen;
1337         struct thread *td;
1338
1339         level = sopt->sopt_level;
1340         op = sopt->sopt_dir;
1341         optname = sopt->sopt_name;
1342         optlen = sopt->sopt_valsize;
1343         td = sopt->sopt_td;
1344         error = 0;
1345         optval = 0;
1346         uproto = (int)so->so_proto->pr_protocol;
1347
1348         if (level == IPPROTO_IPV6) {
1349                 switch (op) {
1350
1351                 case SOPT_SET:
1352                         switch (optname) {
1353                         case IPV6_2292PKTOPTIONS:
1354 #ifdef IPV6_PKTOPTIONS
1355                         case IPV6_PKTOPTIONS:
1356 #endif
1357                         {
1358                                 struct mbuf *m;
1359
1360                                 error = soopt_getm(sopt, &m); /* XXX */
1361                                 if (error != 0)
1362                                         break;
1363                                 error = soopt_mcopyin(sopt, m); /* XXX */
1364                                 if (error != 0)
1365                                         break;
1366                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1367                                                     m, so, sopt);
1368                                 m_freem(m); /* XXX */
1369                                 break;
1370                         }
1371
1372                         /*
1373                          * Use of some Hop-by-Hop options or some
1374                          * Destination options, might require special
1375                          * privilege.  That is, normal applications
1376                          * (without special privilege) might be forbidden
1377                          * from setting certain options in outgoing packets,
1378                          * and might never see certain options in received
1379                          * packets. [RFC 2292 Section 6]
1380                          * KAME specific note:
1381                          *  KAME prevents non-privileged users from sending or
1382                          *  receiving ANY hbh/dst options in order to avoid
1383                          *  overhead of parsing options in the kernel.
1384                          */
1385                         case IPV6_RECVHOPOPTS:
1386                         case IPV6_RECVDSTOPTS:
1387                         case IPV6_RECVRTHDRDSTOPTS:
1388                                 if (td != NULL) {
1389                                         error = priv_check(td,
1390                                             PRIV_NETINET_SETHDROPTS);
1391                                         if (error)
1392                                                 break;
1393                                 }
1394                                 /* FALLTHROUGH */
1395                         case IPV6_UNICAST_HOPS:
1396                         case IPV6_HOPLIMIT:
1397                         case IPV6_FAITH:
1398
1399                         case IPV6_RECVPKTINFO:
1400                         case IPV6_RECVHOPLIMIT:
1401                         case IPV6_RECVRTHDR:
1402                         case IPV6_RECVPATHMTU:
1403                         case IPV6_RECVTCLASS:
1404                         case IPV6_V6ONLY:
1405                         case IPV6_AUTOFLOWLABEL:
1406                         case IPV6_BINDANY:
1407                                 if (optname == IPV6_BINDANY && td != NULL) {
1408                                         error = priv_check(td,
1409                                             PRIV_NETINET_BINDANY);
1410                                         if (error)
1411                                                 break;
1412                                 }
1413
1414                                 if (optlen != sizeof(int)) {
1415                                         error = EINVAL;
1416                                         break;
1417                                 }
1418                                 error = sooptcopyin(sopt, &optval,
1419                                         sizeof optval, sizeof optval);
1420                                 if (error)
1421                                         break;
1422                                 switch (optname) {
1423
1424                                 case IPV6_UNICAST_HOPS:
1425                                         if (optval < -1 || optval >= 256)
1426                                                 error = EINVAL;
1427                                         else {
1428                                                 /* -1 = kernel default */
1429                                                 in6p->in6p_hops = optval;
1430                                                 if ((in6p->inp_vflag &
1431                                                      INP_IPV4) != 0)
1432                                                         in6p->inp_ip_ttl = optval;
1433                                         }
1434                                         break;
1435 #define OPTSET(bit) \
1436 do { \
1437         if (optval) \
1438                 in6p->inp_flags |= (bit); \
1439         else \
1440                 in6p->inp_flags &= ~(bit); \
1441 } while (/*CONSTCOND*/ 0)
1442 #define OPTSET2292(bit) \
1443 do { \
1444         in6p->inp_flags |= IN6P_RFC2292; \
1445         if (optval) \
1446                 in6p->inp_flags |= (bit); \
1447         else \
1448                 in6p->inp_flags &= ~(bit); \
1449 } while (/*CONSTCOND*/ 0)
1450 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1451
1452                                 case IPV6_RECVPKTINFO:
1453                                         /* cannot mix with RFC2292 */
1454                                         if (OPTBIT(IN6P_RFC2292)) {
1455                                                 error = EINVAL;
1456                                                 break;
1457                                         }
1458                                         OPTSET(IN6P_PKTINFO);
1459                                         break;
1460
1461                                 case IPV6_HOPLIMIT:
1462                                 {
1463                                         struct ip6_pktopts **optp;
1464
1465                                         /* cannot mix with RFC2292 */
1466                                         if (OPTBIT(IN6P_RFC2292)) {
1467                                                 error = EINVAL;
1468                                                 break;
1469                                         }
1470                                         optp = &in6p->in6p_outputopts;
1471                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1472                                             (u_char *)&optval, sizeof(optval),
1473                                             optp, (td != NULL) ? td->td_ucred :
1474                                             NULL, uproto);
1475                                         break;
1476                                 }
1477
1478                                 case IPV6_RECVHOPLIMIT:
1479                                         /* cannot mix with RFC2292 */
1480                                         if (OPTBIT(IN6P_RFC2292)) {
1481                                                 error = EINVAL;
1482                                                 break;
1483                                         }
1484                                         OPTSET(IN6P_HOPLIMIT);
1485                                         break;
1486
1487                                 case IPV6_RECVHOPOPTS:
1488                                         /* cannot mix with RFC2292 */
1489                                         if (OPTBIT(IN6P_RFC2292)) {
1490                                                 error = EINVAL;
1491                                                 break;
1492                                         }
1493                                         OPTSET(IN6P_HOPOPTS);
1494                                         break;
1495
1496                                 case IPV6_RECVDSTOPTS:
1497                                         /* cannot mix with RFC2292 */
1498                                         if (OPTBIT(IN6P_RFC2292)) {
1499                                                 error = EINVAL;
1500                                                 break;
1501                                         }
1502                                         OPTSET(IN6P_DSTOPTS);
1503                                         break;
1504
1505                                 case IPV6_RECVRTHDRDSTOPTS:
1506                                         /* cannot mix with RFC2292 */
1507                                         if (OPTBIT(IN6P_RFC2292)) {
1508                                                 error = EINVAL;
1509                                                 break;
1510                                         }
1511                                         OPTSET(IN6P_RTHDRDSTOPTS);
1512                                         break;
1513
1514                                 case IPV6_RECVRTHDR:
1515                                         /* cannot mix with RFC2292 */
1516                                         if (OPTBIT(IN6P_RFC2292)) {
1517                                                 error = EINVAL;
1518                                                 break;
1519                                         }
1520                                         OPTSET(IN6P_RTHDR);
1521                                         break;
1522
1523                                 case IPV6_FAITH:
1524                                         OPTSET(INP_FAITH);
1525                                         break;
1526
1527                                 case IPV6_RECVPATHMTU:
1528                                         /*
1529                                          * We ignore this option for TCP
1530                                          * sockets.
1531                                          * (RFC3542 leaves this case
1532                                          * unspecified.)
1533                                          */
1534                                         if (uproto != IPPROTO_TCP)
1535                                                 OPTSET(IN6P_MTU);
1536                                         break;
1537
1538                                 case IPV6_V6ONLY:
1539                                         /*
1540                                          * make setsockopt(IPV6_V6ONLY)
1541                                          * available only prior to bind(2).
1542                                          * see ipng mailing list, Jun 22 2001.
1543                                          */
1544                                         if (in6p->inp_lport ||
1545                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1546                                                 error = EINVAL;
1547                                                 break;
1548                                         }
1549                                         OPTSET(IN6P_IPV6_V6ONLY);
1550                                         if (optval)
1551                                                 in6p->inp_vflag &= ~INP_IPV4;
1552                                         else
1553                                                 in6p->inp_vflag |= INP_IPV4;
1554                                         break;
1555                                 case IPV6_RECVTCLASS:
1556                                         /* cannot mix with RFC2292 XXX */
1557                                         if (OPTBIT(IN6P_RFC2292)) {
1558                                                 error = EINVAL;
1559                                                 break;
1560                                         }
1561                                         OPTSET(IN6P_TCLASS);
1562                                         break;
1563                                 case IPV6_AUTOFLOWLABEL:
1564                                         OPTSET(IN6P_AUTOFLOWLABEL);
1565                                         break;
1566
1567                                 case IPV6_BINDANY:
1568                                         OPTSET(INP_BINDANY);
1569                                         break;
1570                                 }
1571                                 break;
1572
1573                         case IPV6_TCLASS:
1574                         case IPV6_DONTFRAG:
1575                         case IPV6_USE_MIN_MTU:
1576                         case IPV6_PREFER_TEMPADDR:
1577                                 if (optlen != sizeof(optval)) {
1578                                         error = EINVAL;
1579                                         break;
1580                                 }
1581                                 error = sooptcopyin(sopt, &optval,
1582                                         sizeof optval, sizeof optval);
1583                                 if (error)
1584                                         break;
1585                                 {
1586                                         struct ip6_pktopts **optp;
1587                                         optp = &in6p->in6p_outputopts;
1588                                         error = ip6_pcbopt(optname,
1589                                             (u_char *)&optval, sizeof(optval),
1590                                             optp, (td != NULL) ? td->td_ucred :
1591                                             NULL, uproto);
1592                                         break;
1593                                 }
1594
1595                         case IPV6_2292PKTINFO:
1596                         case IPV6_2292HOPLIMIT:
1597                         case IPV6_2292HOPOPTS:
1598                         case IPV6_2292DSTOPTS:
1599                         case IPV6_2292RTHDR:
1600                                 /* RFC 2292 */
1601                                 if (optlen != sizeof(int)) {
1602                                         error = EINVAL;
1603                                         break;
1604                                 }
1605                                 error = sooptcopyin(sopt, &optval,
1606                                         sizeof optval, sizeof optval);
1607                                 if (error)
1608                                         break;
1609                                 switch (optname) {
1610                                 case IPV6_2292PKTINFO:
1611                                         OPTSET2292(IN6P_PKTINFO);
1612                                         break;
1613                                 case IPV6_2292HOPLIMIT:
1614                                         OPTSET2292(IN6P_HOPLIMIT);
1615                                         break;
1616                                 case IPV6_2292HOPOPTS:
1617                                         /*
1618                                          * Check super-user privilege.
1619                                          * See comments for IPV6_RECVHOPOPTS.
1620                                          */
1621                                         if (td != NULL) {
1622                                                 error = priv_check(td,
1623                                                     PRIV_NETINET_SETHDROPTS);
1624                                                 if (error)
1625                                                         return (error);
1626                                         }
1627                                         OPTSET2292(IN6P_HOPOPTS);
1628                                         break;
1629                                 case IPV6_2292DSTOPTS:
1630                                         if (td != NULL) {
1631                                                 error = priv_check(td,
1632                                                     PRIV_NETINET_SETHDROPTS);
1633                                                 if (error)
1634                                                         return (error);
1635                                         }
1636                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1637                                         break;
1638                                 case IPV6_2292RTHDR:
1639                                         OPTSET2292(IN6P_RTHDR);
1640                                         break;
1641                                 }
1642                                 break;
1643                         case IPV6_PKTINFO:
1644                         case IPV6_HOPOPTS:
1645                         case IPV6_RTHDR:
1646                         case IPV6_DSTOPTS:
1647                         case IPV6_RTHDRDSTOPTS:
1648                         case IPV6_NEXTHOP:
1649                         {
1650                                 /* new advanced API (RFC3542) */
1651                                 u_char *optbuf;
1652                                 u_char optbuf_storage[MCLBYTES];
1653                                 int optlen;
1654                                 struct ip6_pktopts **optp;
1655
1656                                 /* cannot mix with RFC2292 */
1657                                 if (OPTBIT(IN6P_RFC2292)) {
1658                                         error = EINVAL;
1659                                         break;
1660                                 }
1661
1662                                 /*
1663                                  * We only ensure valsize is not too large
1664                                  * here.  Further validation will be done
1665                                  * later.
1666                                  */
1667                                 error = sooptcopyin(sopt, optbuf_storage,
1668                                     sizeof(optbuf_storage), 0);
1669                                 if (error)
1670                                         break;
1671                                 optlen = sopt->sopt_valsize;
1672                                 optbuf = optbuf_storage;
1673                                 optp = &in6p->in6p_outputopts;
1674                                 error = ip6_pcbopt(optname, optbuf, optlen,
1675                                     optp, (td != NULL) ? td->td_ucred : NULL,
1676                                     uproto);
1677                                 break;
1678                         }
1679 #undef OPTSET
1680
1681                         case IPV6_MULTICAST_IF:
1682                         case IPV6_MULTICAST_HOPS:
1683                         case IPV6_MULTICAST_LOOP:
1684                         case IPV6_JOIN_GROUP:
1685                         case IPV6_LEAVE_GROUP:
1686                         case IPV6_MSFILTER:
1687                         case MCAST_BLOCK_SOURCE:
1688                         case MCAST_UNBLOCK_SOURCE:
1689                         case MCAST_JOIN_GROUP:
1690                         case MCAST_LEAVE_GROUP:
1691                         case MCAST_JOIN_SOURCE_GROUP:
1692                         case MCAST_LEAVE_SOURCE_GROUP:
1693                                 error = ip6_setmoptions(in6p, sopt);
1694                                 break;
1695
1696                         case IPV6_PORTRANGE:
1697                                 error = sooptcopyin(sopt, &optval,
1698                                     sizeof optval, sizeof optval);
1699                                 if (error)
1700                                         break;
1701
1702                                 switch (optval) {
1703                                 case IPV6_PORTRANGE_DEFAULT:
1704                                         in6p->inp_flags &= ~(INP_LOWPORT);
1705                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1706                                         break;
1707
1708                                 case IPV6_PORTRANGE_HIGH:
1709                                         in6p->inp_flags &= ~(INP_LOWPORT);
1710                                         in6p->inp_flags |= INP_HIGHPORT;
1711                                         break;
1712
1713                                 case IPV6_PORTRANGE_LOW:
1714                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1715                                         in6p->inp_flags |= INP_LOWPORT;
1716                                         break;
1717
1718                                 default:
1719                                         error = EINVAL;
1720                                         break;
1721                                 }
1722                                 break;
1723
1724 #ifdef IPSEC
1725                         case IPV6_IPSEC_POLICY:
1726                         {
1727                                 caddr_t req;
1728                                 struct mbuf *m;
1729
1730                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1731                                         break;
1732                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1733                                         break;
1734                                 req = mtod(m, caddr_t);
1735                                 error = ipsec_set_policy(in6p, optname, req,
1736                                     m->m_len, (sopt->sopt_td != NULL) ?
1737                                     sopt->sopt_td->td_ucred : NULL);
1738                                 m_freem(m);
1739                                 break;
1740                         }
1741 #endif /* IPSEC */
1742
1743                         default:
1744                                 error = ENOPROTOOPT;
1745                                 break;
1746                         }
1747                         break;
1748
1749                 case SOPT_GET:
1750                         switch (optname) {
1751
1752                         case IPV6_2292PKTOPTIONS:
1753 #ifdef IPV6_PKTOPTIONS
1754                         case IPV6_PKTOPTIONS:
1755 #endif
1756                                 /*
1757                                  * RFC3542 (effectively) deprecated the
1758                                  * semantics of the 2292-style pktoptions.
1759                                  * Since it was not reliable in nature (i.e.,
1760                                  * applications had to expect the lack of some
1761                                  * information after all), it would make sense
1762                                  * to simplify this part by always returning
1763                                  * empty data.
1764                                  */
1765                                 sopt->sopt_valsize = 0;
1766                                 break;
1767
1768                         case IPV6_RECVHOPOPTS:
1769                         case IPV6_RECVDSTOPTS:
1770                         case IPV6_RECVRTHDRDSTOPTS:
1771                         case IPV6_UNICAST_HOPS:
1772                         case IPV6_RECVPKTINFO:
1773                         case IPV6_RECVHOPLIMIT:
1774                         case IPV6_RECVRTHDR:
1775                         case IPV6_RECVPATHMTU:
1776
1777                         case IPV6_FAITH:
1778                         case IPV6_V6ONLY:
1779                         case IPV6_PORTRANGE:
1780                         case IPV6_RECVTCLASS:
1781                         case IPV6_AUTOFLOWLABEL:
1782                                 switch (optname) {
1783
1784                                 case IPV6_RECVHOPOPTS:
1785                                         optval = OPTBIT(IN6P_HOPOPTS);
1786                                         break;
1787
1788                                 case IPV6_RECVDSTOPTS:
1789                                         optval = OPTBIT(IN6P_DSTOPTS);
1790                                         break;
1791
1792                                 case IPV6_RECVRTHDRDSTOPTS:
1793                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1794                                         break;
1795
1796                                 case IPV6_UNICAST_HOPS:
1797                                         optval = in6p->in6p_hops;
1798                                         break;
1799
1800                                 case IPV6_RECVPKTINFO:
1801                                         optval = OPTBIT(IN6P_PKTINFO);
1802                                         break;
1803
1804                                 case IPV6_RECVHOPLIMIT:
1805                                         optval = OPTBIT(IN6P_HOPLIMIT);
1806                                         break;
1807
1808                                 case IPV6_RECVRTHDR:
1809                                         optval = OPTBIT(IN6P_RTHDR);
1810                                         break;
1811
1812                                 case IPV6_RECVPATHMTU:
1813                                         optval = OPTBIT(IN6P_MTU);
1814                                         break;
1815
1816                                 case IPV6_FAITH:
1817                                         optval = OPTBIT(INP_FAITH);
1818                                         break;
1819
1820                                 case IPV6_V6ONLY:
1821                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1822                                         break;
1823
1824                                 case IPV6_PORTRANGE:
1825                                     {
1826                                         int flags;
1827                                         flags = in6p->inp_flags;
1828                                         if (flags & INP_HIGHPORT)
1829                                                 optval = IPV6_PORTRANGE_HIGH;
1830                                         else if (flags & INP_LOWPORT)
1831                                                 optval = IPV6_PORTRANGE_LOW;
1832                                         else
1833                                                 optval = 0;
1834                                         break;
1835                                     }
1836                                 case IPV6_RECVTCLASS:
1837                                         optval = OPTBIT(IN6P_TCLASS);
1838                                         break;
1839
1840                                 case IPV6_AUTOFLOWLABEL:
1841                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1842                                         break;
1843
1844                                 case IPV6_BINDANY:
1845                                         optval = OPTBIT(INP_BINDANY);
1846                                         break;
1847                                 }
1848                                 if (error)
1849                                         break;
1850                                 error = sooptcopyout(sopt, &optval,
1851                                         sizeof optval);
1852                                 break;
1853
1854                         case IPV6_PATHMTU:
1855                         {
1856                                 u_long pmtu = 0;
1857                                 struct ip6_mtuinfo mtuinfo;
1858                                 struct route_in6 sro;
1859
1860                                 bzero(&sro, sizeof(sro));
1861
1862                                 if (!(so->so_state & SS_ISCONNECTED))
1863                                         return (ENOTCONN);
1864                                 /*
1865                                  * XXX: we dot not consider the case of source
1866                                  * routing, or optional information to specify
1867                                  * the outgoing interface.
1868                                  */
1869                                 error = ip6_getpmtu(&sro, NULL, NULL,
1870                                     &in6p->in6p_faddr, &pmtu, NULL);
1871                                 if (sro.ro_rt)
1872                                         RTFREE(sro.ro_rt);
1873                                 if (error)
1874                                         break;
1875                                 if (pmtu > IPV6_MAXPACKET)
1876                                         pmtu = IPV6_MAXPACKET;
1877
1878                                 bzero(&mtuinfo, sizeof(mtuinfo));
1879                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1880                                 optdata = (void *)&mtuinfo;
1881                                 optdatalen = sizeof(mtuinfo);
1882                                 error = sooptcopyout(sopt, optdata,
1883                                     optdatalen);
1884                                 break;
1885                         }
1886
1887                         case IPV6_2292PKTINFO:
1888                         case IPV6_2292HOPLIMIT:
1889                         case IPV6_2292HOPOPTS:
1890                         case IPV6_2292RTHDR:
1891                         case IPV6_2292DSTOPTS:
1892                                 switch (optname) {
1893                                 case IPV6_2292PKTINFO:
1894                                         optval = OPTBIT(IN6P_PKTINFO);
1895                                         break;
1896                                 case IPV6_2292HOPLIMIT:
1897                                         optval = OPTBIT(IN6P_HOPLIMIT);
1898                                         break;
1899                                 case IPV6_2292HOPOPTS:
1900                                         optval = OPTBIT(IN6P_HOPOPTS);
1901                                         break;
1902                                 case IPV6_2292RTHDR:
1903                                         optval = OPTBIT(IN6P_RTHDR);
1904                                         break;
1905                                 case IPV6_2292DSTOPTS:
1906                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1907                                         break;
1908                                 }
1909                                 error = sooptcopyout(sopt, &optval,
1910                                     sizeof optval);
1911                                 break;
1912                         case IPV6_PKTINFO:
1913                         case IPV6_HOPOPTS:
1914                         case IPV6_RTHDR:
1915                         case IPV6_DSTOPTS:
1916                         case IPV6_RTHDRDSTOPTS:
1917                         case IPV6_NEXTHOP:
1918                         case IPV6_TCLASS:
1919                         case IPV6_DONTFRAG:
1920                         case IPV6_USE_MIN_MTU:
1921                         case IPV6_PREFER_TEMPADDR:
1922                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
1923                                     optname, sopt);
1924                                 break;
1925
1926                         case IPV6_MULTICAST_IF:
1927                         case IPV6_MULTICAST_HOPS:
1928                         case IPV6_MULTICAST_LOOP:
1929                         case IPV6_MSFILTER:
1930                                 error = ip6_getmoptions(in6p, sopt);
1931                                 break;
1932
1933 #ifdef IPSEC
1934                         case IPV6_IPSEC_POLICY:
1935                           {
1936                                 caddr_t req = NULL;
1937                                 size_t len = 0;
1938                                 struct mbuf *m = NULL;
1939                                 struct mbuf **mp = &m;
1940                                 size_t ovalsize = sopt->sopt_valsize;
1941                                 caddr_t oval = (caddr_t)sopt->sopt_val;
1942
1943                                 error = soopt_getm(sopt, &m); /* XXX */
1944                                 if (error != 0)
1945                                         break;
1946                                 error = soopt_mcopyin(sopt, m); /* XXX */
1947                                 if (error != 0)
1948                                         break;
1949                                 sopt->sopt_valsize = ovalsize;
1950                                 sopt->sopt_val = oval;
1951                                 if (m) {
1952                                         req = mtod(m, caddr_t);
1953                                         len = m->m_len;
1954                                 }
1955                                 error = ipsec_get_policy(in6p, req, len, mp);
1956                                 if (error == 0)
1957                                         error = soopt_mcopyout(sopt, m); /* XXX */
1958                                 if (error == 0 && m)
1959                                         m_freem(m);
1960                                 break;
1961                           }
1962 #endif /* IPSEC */
1963
1964                         default:
1965                                 error = ENOPROTOOPT;
1966                                 break;
1967                         }
1968                         break;
1969                 }
1970         } else {                /* level != IPPROTO_IPV6 */
1971                 error = EINVAL;
1972         }
1973         return (error);
1974 }
1975
1976 int
1977 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
1978 {
1979         int error = 0, optval, optlen;
1980         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
1981         struct inpcb *in6p = sotoinpcb(so);
1982         int level, op, optname;
1983
1984         level = sopt->sopt_level;
1985         op = sopt->sopt_dir;
1986         optname = sopt->sopt_name;
1987         optlen = sopt->sopt_valsize;
1988
1989         if (level != IPPROTO_IPV6) {
1990                 return (EINVAL);
1991         }
1992
1993         switch (optname) {
1994         case IPV6_CHECKSUM:
1995                 /*
1996                  * For ICMPv6 sockets, no modification allowed for checksum
1997                  * offset, permit "no change" values to help existing apps.
1998                  *
1999                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2000                  * for an ICMPv6 socket will fail."
2001                  * The current behavior does not meet RFC3542.
2002                  */
2003                 switch (op) {
2004                 case SOPT_SET:
2005                         if (optlen != sizeof(int)) {
2006                                 error = EINVAL;
2007                                 break;
2008                         }
2009                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2010                                             sizeof(optval));
2011                         if (error)
2012                                 break;
2013                         if ((optval % 2) != 0) {
2014                                 /* the API assumes even offset values */
2015                                 error = EINVAL;
2016                         } else if (so->so_proto->pr_protocol ==
2017                             IPPROTO_ICMPV6) {
2018                                 if (optval != icmp6off)
2019                                         error = EINVAL;
2020                         } else
2021                                 in6p->in6p_cksum = optval;
2022                         break;
2023
2024                 case SOPT_GET:
2025                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2026                                 optval = icmp6off;
2027                         else
2028                                 optval = in6p->in6p_cksum;
2029
2030                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2031                         break;
2032
2033                 default:
2034                         error = EINVAL;
2035                         break;
2036                 }
2037                 break;
2038
2039         default:
2040                 error = ENOPROTOOPT;
2041                 break;
2042         }
2043
2044         return (error);
2045 }
2046
2047 /*
2048  * Set up IP6 options in pcb for insertion in output packets or
2049  * specifying behavior of outgoing packets.
2050  */
2051 static int
2052 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2053     struct socket *so, struct sockopt *sopt)
2054 {
2055         struct ip6_pktopts *opt = *pktopt;
2056         int error = 0;
2057         struct thread *td = sopt->sopt_td;
2058
2059         /* turn off any old options. */
2060         if (opt) {
2061 #ifdef DIAGNOSTIC
2062                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2063                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2064                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2065                         printf("ip6_pcbopts: all specified options are cleared.\n");
2066 #endif
2067                 ip6_clearpktopts(opt, -1);
2068         } else
2069                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2070         *pktopt = NULL;
2071
2072         if (!m || m->m_len == 0) {
2073                 /*
2074                  * Only turning off any previous options, regardless of
2075                  * whether the opt is just created or given.
2076                  */
2077                 free(opt, M_IP6OPT);
2078                 return (0);
2079         }
2080
2081         /*  set options specified by user. */
2082         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2083             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2084                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2085                 free(opt, M_IP6OPT);
2086                 return (error);
2087         }
2088         *pktopt = opt;
2089         return (0);
2090 }
2091
2092 /*
2093  * initialize ip6_pktopts.  beware that there are non-zero default values in
2094  * the struct.
2095  */
2096 void
2097 ip6_initpktopts(struct ip6_pktopts *opt)
2098 {
2099
2100         bzero(opt, sizeof(*opt));
2101         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2102         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2103         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2104         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2105 }
2106
2107 static int
2108 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2109     struct ucred *cred, int uproto)
2110 {
2111         struct ip6_pktopts *opt;
2112
2113         if (*pktopt == NULL) {
2114                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2115                     M_WAITOK);
2116                 ip6_initpktopts(*pktopt);
2117         }
2118         opt = *pktopt;
2119
2120         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2121 }
2122
2123 static int
2124 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2125 {
2126         void *optdata = NULL;
2127         int optdatalen = 0;
2128         struct ip6_ext *ip6e;
2129         int error = 0;
2130         struct in6_pktinfo null_pktinfo;
2131         int deftclass = 0, on;
2132         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2133         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2134
2135         switch (optname) {
2136         case IPV6_PKTINFO:
2137                 if (pktopt && pktopt->ip6po_pktinfo)
2138                         optdata = (void *)pktopt->ip6po_pktinfo;
2139                 else {
2140                         /* XXX: we don't have to do this every time... */
2141                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2142                         optdata = (void *)&null_pktinfo;
2143                 }
2144                 optdatalen = sizeof(struct in6_pktinfo);
2145                 break;
2146         case IPV6_TCLASS:
2147                 if (pktopt && pktopt->ip6po_tclass >= 0)
2148                         optdata = (void *)&pktopt->ip6po_tclass;
2149                 else
2150                         optdata = (void *)&deftclass;
2151                 optdatalen = sizeof(int);
2152                 break;
2153         case IPV6_HOPOPTS:
2154                 if (pktopt && pktopt->ip6po_hbh) {
2155                         optdata = (void *)pktopt->ip6po_hbh;
2156                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2157                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2158                 }
2159                 break;
2160         case IPV6_RTHDR:
2161                 if (pktopt && pktopt->ip6po_rthdr) {
2162                         optdata = (void *)pktopt->ip6po_rthdr;
2163                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2164                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2165                 }
2166                 break;
2167         case IPV6_RTHDRDSTOPTS:
2168                 if (pktopt && pktopt->ip6po_dest1) {
2169                         optdata = (void *)pktopt->ip6po_dest1;
2170                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2171                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2172                 }
2173                 break;
2174         case IPV6_DSTOPTS:
2175                 if (pktopt && pktopt->ip6po_dest2) {
2176                         optdata = (void *)pktopt->ip6po_dest2;
2177                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2178                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2179                 }
2180                 break;
2181         case IPV6_NEXTHOP:
2182                 if (pktopt && pktopt->ip6po_nexthop) {
2183                         optdata = (void *)pktopt->ip6po_nexthop;
2184                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2185                 }
2186                 break;
2187         case IPV6_USE_MIN_MTU:
2188                 if (pktopt)
2189                         optdata = (void *)&pktopt->ip6po_minmtu;
2190                 else
2191                         optdata = (void *)&defminmtu;
2192                 optdatalen = sizeof(int);
2193                 break;
2194         case IPV6_DONTFRAG:
2195                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2196                         on = 1;
2197                 else
2198                         on = 0;
2199                 optdata = (void *)&on;
2200                 optdatalen = sizeof(on);
2201                 break;
2202         case IPV6_PREFER_TEMPADDR:
2203                 if (pktopt)
2204                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2205                 else
2206                         optdata = (void *)&defpreftemp;
2207                 optdatalen = sizeof(int);
2208                 break;
2209         default:                /* should not happen */
2210 #ifdef DIAGNOSTIC
2211                 panic("ip6_getpcbopt: unexpected option\n");
2212 #endif
2213                 return (ENOPROTOOPT);
2214         }
2215
2216         error = sooptcopyout(sopt, optdata, optdatalen);
2217
2218         return (error);
2219 }
2220
2221 void
2222 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2223 {
2224         if (pktopt == NULL)
2225                 return;
2226
2227         if (optname == -1 || optname == IPV6_PKTINFO) {
2228                 if (pktopt->ip6po_pktinfo)
2229                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2230                 pktopt->ip6po_pktinfo = NULL;
2231         }
2232         if (optname == -1 || optname == IPV6_HOPLIMIT)
2233                 pktopt->ip6po_hlim = -1;
2234         if (optname == -1 || optname == IPV6_TCLASS)
2235                 pktopt->ip6po_tclass = -1;
2236         if (optname == -1 || optname == IPV6_NEXTHOP) {
2237                 if (pktopt->ip6po_nextroute.ro_rt) {
2238                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2239                         pktopt->ip6po_nextroute.ro_rt = NULL;
2240                 }
2241                 if (pktopt->ip6po_nexthop)
2242                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2243                 pktopt->ip6po_nexthop = NULL;
2244         }
2245         if (optname == -1 || optname == IPV6_HOPOPTS) {
2246                 if (pktopt->ip6po_hbh)
2247                         free(pktopt->ip6po_hbh, M_IP6OPT);
2248                 pktopt->ip6po_hbh = NULL;
2249         }
2250         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2251                 if (pktopt->ip6po_dest1)
2252                         free(pktopt->ip6po_dest1, M_IP6OPT);
2253                 pktopt->ip6po_dest1 = NULL;
2254         }
2255         if (optname == -1 || optname == IPV6_RTHDR) {
2256                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2257                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2258                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2259                 if (pktopt->ip6po_route.ro_rt) {
2260                         RTFREE(pktopt->ip6po_route.ro_rt);
2261                         pktopt->ip6po_route.ro_rt = NULL;
2262                 }
2263         }
2264         if (optname == -1 || optname == IPV6_DSTOPTS) {
2265                 if (pktopt->ip6po_dest2)
2266                         free(pktopt->ip6po_dest2, M_IP6OPT);
2267                 pktopt->ip6po_dest2 = NULL;
2268         }
2269 }
2270
2271 #define PKTOPT_EXTHDRCPY(type) \
2272 do {\
2273         if (src->type) {\
2274                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2275                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2276                 if (dst->type == NULL && canwait == M_NOWAIT)\
2277                         goto bad;\
2278                 bcopy(src->type, dst->type, hlen);\
2279         }\
2280 } while (/*CONSTCOND*/ 0)
2281
2282 static int
2283 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2284 {
2285         if (dst == NULL || src == NULL)  {
2286                 printf("ip6_clearpktopts: invalid argument\n");
2287                 return (EINVAL);
2288         }
2289
2290         dst->ip6po_hlim = src->ip6po_hlim;
2291         dst->ip6po_tclass = src->ip6po_tclass;
2292         dst->ip6po_flags = src->ip6po_flags;
2293         if (src->ip6po_pktinfo) {
2294                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2295                     M_IP6OPT, canwait);
2296                 if (dst->ip6po_pktinfo == NULL)
2297                         goto bad;
2298                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2299         }
2300         if (src->ip6po_nexthop) {
2301                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2302                     M_IP6OPT, canwait);
2303                 if (dst->ip6po_nexthop == NULL)
2304                         goto bad;
2305                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2306                     src->ip6po_nexthop->sa_len);
2307         }
2308         PKTOPT_EXTHDRCPY(ip6po_hbh);
2309         PKTOPT_EXTHDRCPY(ip6po_dest1);
2310         PKTOPT_EXTHDRCPY(ip6po_dest2);
2311         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2312         return (0);
2313
2314   bad:
2315         ip6_clearpktopts(dst, -1);
2316         return (ENOBUFS);
2317 }
2318 #undef PKTOPT_EXTHDRCPY
2319
2320 struct ip6_pktopts *
2321 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2322 {
2323         int error;
2324         struct ip6_pktopts *dst;
2325
2326         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2327         if (dst == NULL)
2328                 return (NULL);
2329         ip6_initpktopts(dst);
2330
2331         if ((error = copypktopts(dst, src, canwait)) != 0) {
2332                 free(dst, M_IP6OPT);
2333                 return (NULL);
2334         }
2335
2336         return (dst);
2337 }
2338
2339 void
2340 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2341 {
2342         if (pktopt == NULL)
2343                 return;
2344
2345         ip6_clearpktopts(pktopt, -1);
2346
2347         free(pktopt, M_IP6OPT);
2348 }
2349
2350 /*
2351  * Set IPv6 outgoing packet options based on advanced API.
2352  */
2353 int
2354 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2355     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2356 {
2357         struct cmsghdr *cm = 0;
2358
2359         if (control == NULL || opt == NULL)
2360                 return (EINVAL);
2361
2362         ip6_initpktopts(opt);
2363         if (stickyopt) {
2364                 int error;
2365
2366                 /*
2367                  * If stickyopt is provided, make a local copy of the options
2368                  * for this particular packet, then override them by ancillary
2369                  * objects.
2370                  * XXX: copypktopts() does not copy the cached route to a next
2371                  * hop (if any).  This is not very good in terms of efficiency,
2372                  * but we can allow this since this option should be rarely
2373                  * used.
2374                  */
2375                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2376                         return (error);
2377         }
2378
2379         /*
2380          * XXX: Currently, we assume all the optional information is stored
2381          * in a single mbuf.
2382          */
2383         if (control->m_next)
2384                 return (EINVAL);
2385
2386         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2387             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2388                 int error;
2389
2390                 if (control->m_len < CMSG_LEN(0))
2391                         return (EINVAL);
2392
2393                 cm = mtod(control, struct cmsghdr *);
2394                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2395                         return (EINVAL);
2396                 if (cm->cmsg_level != IPPROTO_IPV6)
2397                         continue;
2398
2399                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2400                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2401                 if (error)
2402                         return (error);
2403         }
2404
2405         return (0);
2406 }
2407
2408 /*
2409  * Set a particular packet option, as a sticky option or an ancillary data
2410  * item.  "len" can be 0 only when it's a sticky option.
2411  * We have 4 cases of combination of "sticky" and "cmsg":
2412  * "sticky=0, cmsg=0": impossible
2413  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2414  * "sticky=1, cmsg=0": RFC3542 socket option
2415  * "sticky=1, cmsg=1": RFC2292 socket option
2416  */
2417 static int
2418 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2419     struct ucred *cred, int sticky, int cmsg, int uproto)
2420 {
2421         int minmtupolicy, preftemp;
2422         int error;
2423
2424         if (!sticky && !cmsg) {
2425 #ifdef DIAGNOSTIC
2426                 printf("ip6_setpktopt: impossible case\n");
2427 #endif
2428                 return (EINVAL);
2429         }
2430
2431         /*
2432          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2433          * not be specified in the context of RFC3542.  Conversely,
2434          * RFC3542 types should not be specified in the context of RFC2292.
2435          */
2436         if (!cmsg) {
2437                 switch (optname) {
2438                 case IPV6_2292PKTINFO:
2439                 case IPV6_2292HOPLIMIT:
2440                 case IPV6_2292NEXTHOP:
2441                 case IPV6_2292HOPOPTS:
2442                 case IPV6_2292DSTOPTS:
2443                 case IPV6_2292RTHDR:
2444                 case IPV6_2292PKTOPTIONS:
2445                         return (ENOPROTOOPT);
2446                 }
2447         }
2448         if (sticky && cmsg) {
2449                 switch (optname) {
2450                 case IPV6_PKTINFO:
2451                 case IPV6_HOPLIMIT:
2452                 case IPV6_NEXTHOP:
2453                 case IPV6_HOPOPTS:
2454                 case IPV6_DSTOPTS:
2455                 case IPV6_RTHDRDSTOPTS:
2456                 case IPV6_RTHDR:
2457                 case IPV6_USE_MIN_MTU:
2458                 case IPV6_DONTFRAG:
2459                 case IPV6_TCLASS:
2460                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2461                         return (ENOPROTOOPT);
2462                 }
2463         }
2464
2465         switch (optname) {
2466         case IPV6_2292PKTINFO:
2467         case IPV6_PKTINFO:
2468         {
2469                 struct ifnet *ifp = NULL;
2470                 struct in6_pktinfo *pktinfo;
2471
2472                 if (len != sizeof(struct in6_pktinfo))
2473                         return (EINVAL);
2474
2475                 pktinfo = (struct in6_pktinfo *)buf;
2476
2477                 /*
2478                  * An application can clear any sticky IPV6_PKTINFO option by
2479                  * doing a "regular" setsockopt with ipi6_addr being
2480                  * in6addr_any and ipi6_ifindex being zero.
2481                  * [RFC 3542, Section 6]
2482                  */
2483                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2484                     pktinfo->ipi6_ifindex == 0 &&
2485                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2486                         ip6_clearpktopts(opt, optname);
2487                         break;
2488                 }
2489
2490                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2491                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2492                         return (EINVAL);
2493                 }
2494
2495                 /* validate the interface index if specified. */
2496                 if (pktinfo->ipi6_ifindex > V_if_index ||
2497                     pktinfo->ipi6_ifindex < 0) {
2498                          return (ENXIO);
2499                 }
2500                 if (pktinfo->ipi6_ifindex) {
2501                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2502                         if (ifp == NULL)
2503                                 return (ENXIO);
2504                 }
2505
2506                 /*
2507                  * We store the address anyway, and let in6_selectsrc()
2508                  * validate the specified address.  This is because ipi6_addr
2509                  * may not have enough information about its scope zone, and
2510                  * we may need additional information (such as outgoing
2511                  * interface or the scope zone of a destination address) to
2512                  * disambiguate the scope.
2513                  * XXX: the delay of the validation may confuse the
2514                  * application when it is used as a sticky option.
2515                  */
2516                 if (opt->ip6po_pktinfo == NULL) {
2517                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2518                             M_IP6OPT, M_NOWAIT);
2519                         if (opt->ip6po_pktinfo == NULL)
2520                                 return (ENOBUFS);
2521                 }
2522                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2523                 break;
2524         }
2525
2526         case IPV6_2292HOPLIMIT:
2527         case IPV6_HOPLIMIT:
2528         {
2529                 int *hlimp;
2530
2531                 /*
2532                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2533                  * to simplify the ordering among hoplimit options.
2534                  */
2535                 if (optname == IPV6_HOPLIMIT && sticky)
2536                         return (ENOPROTOOPT);
2537
2538                 if (len != sizeof(int))
2539                         return (EINVAL);
2540                 hlimp = (int *)buf;
2541                 if (*hlimp < -1 || *hlimp > 255)
2542                         return (EINVAL);
2543
2544                 opt->ip6po_hlim = *hlimp;
2545                 break;
2546         }
2547
2548         case IPV6_TCLASS:
2549         {
2550                 int tclass;
2551
2552                 if (len != sizeof(int))
2553                         return (EINVAL);
2554                 tclass = *(int *)buf;
2555                 if (tclass < -1 || tclass > 255)
2556                         return (EINVAL);
2557
2558                 opt->ip6po_tclass = tclass;
2559                 break;
2560         }
2561
2562         case IPV6_2292NEXTHOP:
2563         case IPV6_NEXTHOP:
2564                 if (cred != NULL) {
2565                         error = priv_check_cred(cred,
2566                             PRIV_NETINET_SETHDROPTS, 0);
2567                         if (error)
2568                                 return (error);
2569                 }
2570
2571                 if (len == 0) { /* just remove the option */
2572                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2573                         break;
2574                 }
2575
2576                 /* check if cmsg_len is large enough for sa_len */
2577                 if (len < sizeof(struct sockaddr) || len < *buf)
2578                         return (EINVAL);
2579
2580                 switch (((struct sockaddr *)buf)->sa_family) {
2581                 case AF_INET6:
2582                 {
2583                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2584                         int error;
2585
2586                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2587                                 return (EINVAL);
2588
2589                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2590                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2591                                 return (EINVAL);
2592                         }
2593                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2594                             != 0) {
2595                                 return (error);
2596                         }
2597                         break;
2598                 }
2599                 case AF_LINK:   /* should eventually be supported */
2600                 default:
2601                         return (EAFNOSUPPORT);
2602                 }
2603
2604                 /* turn off the previous option, then set the new option. */
2605                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2606                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2607                 if (opt->ip6po_nexthop == NULL)
2608                         return (ENOBUFS);
2609                 bcopy(buf, opt->ip6po_nexthop, *buf);
2610                 break;
2611
2612         case IPV6_2292HOPOPTS:
2613         case IPV6_HOPOPTS:
2614         {
2615                 struct ip6_hbh *hbh;
2616                 int hbhlen;
2617
2618                 /*
2619                  * XXX: We don't allow a non-privileged user to set ANY HbH
2620                  * options, since per-option restriction has too much
2621                  * overhead.
2622                  */
2623                 if (cred != NULL) {
2624                         error = priv_check_cred(cred,
2625                             PRIV_NETINET_SETHDROPTS, 0);
2626                         if (error)
2627                                 return (error);
2628                 }
2629
2630                 if (len == 0) {
2631                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2632                         break;  /* just remove the option */
2633                 }
2634
2635                 /* message length validation */
2636                 if (len < sizeof(struct ip6_hbh))
2637                         return (EINVAL);
2638                 hbh = (struct ip6_hbh *)buf;
2639                 hbhlen = (hbh->ip6h_len + 1) << 3;
2640                 if (len != hbhlen)
2641                         return (EINVAL);
2642
2643                 /* turn off the previous option, then set the new option. */
2644                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2645                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2646                 if (opt->ip6po_hbh == NULL)
2647                         return (ENOBUFS);
2648                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2649
2650                 break;
2651         }
2652
2653         case IPV6_2292DSTOPTS:
2654         case IPV6_DSTOPTS:
2655         case IPV6_RTHDRDSTOPTS:
2656         {
2657                 struct ip6_dest *dest, **newdest = NULL;
2658                 int destlen;
2659
2660                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2661                         error = priv_check_cred(cred,
2662                             PRIV_NETINET_SETHDROPTS, 0);
2663                         if (error)
2664                                 return (error);
2665                 }
2666
2667                 if (len == 0) {
2668                         ip6_clearpktopts(opt, optname);
2669                         break;  /* just remove the option */
2670                 }
2671
2672                 /* message length validation */
2673                 if (len < sizeof(struct ip6_dest))
2674                         return (EINVAL);
2675                 dest = (struct ip6_dest *)buf;
2676                 destlen = (dest->ip6d_len + 1) << 3;
2677                 if (len != destlen)
2678                         return (EINVAL);
2679
2680                 /*
2681                  * Determine the position that the destination options header
2682                  * should be inserted; before or after the routing header.
2683                  */
2684                 switch (optname) {
2685                 case IPV6_2292DSTOPTS:
2686                         /*
2687                          * The old advacned API is ambiguous on this point.
2688                          * Our approach is to determine the position based
2689                          * according to the existence of a routing header.
2690                          * Note, however, that this depends on the order of the
2691                          * extension headers in the ancillary data; the 1st
2692                          * part of the destination options header must appear
2693                          * before the routing header in the ancillary data,
2694                          * too.
2695                          * RFC3542 solved the ambiguity by introducing
2696                          * separate ancillary data or option types.
2697                          */
2698                         if (opt->ip6po_rthdr == NULL)
2699                                 newdest = &opt->ip6po_dest1;
2700                         else
2701                                 newdest = &opt->ip6po_dest2;
2702                         break;
2703                 case IPV6_RTHDRDSTOPTS:
2704                         newdest = &opt->ip6po_dest1;
2705                         break;
2706                 case IPV6_DSTOPTS:
2707                         newdest = &opt->ip6po_dest2;
2708                         break;
2709                 }
2710
2711                 /* turn off the previous option, then set the new option. */
2712                 ip6_clearpktopts(opt, optname);
2713                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2714                 if (*newdest == NULL)
2715                         return (ENOBUFS);
2716                 bcopy(dest, *newdest, destlen);
2717
2718                 break;
2719         }
2720
2721         case IPV6_2292RTHDR:
2722         case IPV6_RTHDR:
2723         {
2724                 struct ip6_rthdr *rth;
2725                 int rthlen;
2726
2727                 if (len == 0) {
2728                         ip6_clearpktopts(opt, IPV6_RTHDR);
2729                         break;  /* just remove the option */
2730                 }
2731
2732                 /* message length validation */
2733                 if (len < sizeof(struct ip6_rthdr))
2734                         return (EINVAL);
2735                 rth = (struct ip6_rthdr *)buf;
2736                 rthlen = (rth->ip6r_len + 1) << 3;
2737                 if (len != rthlen)
2738                         return (EINVAL);
2739
2740                 switch (rth->ip6r_type) {
2741                 case IPV6_RTHDR_TYPE_0:
2742                         if (rth->ip6r_len == 0) /* must contain one addr */
2743                                 return (EINVAL);
2744                         if (rth->ip6r_len % 2) /* length must be even */
2745                                 return (EINVAL);
2746                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2747                                 return (EINVAL);
2748                         break;
2749                 default:
2750                         return (EINVAL);        /* not supported */
2751                 }
2752
2753                 /* turn off the previous option */
2754                 ip6_clearpktopts(opt, IPV6_RTHDR);
2755                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2756                 if (opt->ip6po_rthdr == NULL)
2757                         return (ENOBUFS);
2758                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2759
2760                 break;
2761         }
2762
2763         case IPV6_USE_MIN_MTU:
2764                 if (len != sizeof(int))
2765                         return (EINVAL);
2766                 minmtupolicy = *(int *)buf;
2767                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2768                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2769                     minmtupolicy != IP6PO_MINMTU_ALL) {
2770                         return (EINVAL);
2771                 }
2772                 opt->ip6po_minmtu = minmtupolicy;
2773                 break;
2774
2775         case IPV6_DONTFRAG:
2776                 if (len != sizeof(int))
2777                         return (EINVAL);
2778
2779                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2780                         /*
2781                          * we ignore this option for TCP sockets.
2782                          * (RFC3542 leaves this case unspecified.)
2783                          */
2784                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2785                 } else
2786                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2787                 break;
2788
2789         case IPV6_PREFER_TEMPADDR:
2790                 if (len != sizeof(int))
2791                         return (EINVAL);
2792                 preftemp = *(int *)buf;
2793                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2794                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2795                     preftemp != IP6PO_TEMPADDR_PREFER) {
2796                         return (EINVAL);
2797                 }
2798                 opt->ip6po_prefer_tempaddr = preftemp;
2799                 break;
2800
2801         default:
2802                 return (ENOPROTOOPT);
2803         } /* end of switch */
2804
2805         return (0);
2806 }
2807
2808 /*
2809  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2810  * packet to the input queue of a specified interface.  Note that this
2811  * calls the output routine of the loopback "driver", but with an interface
2812  * pointer that might NOT be &loif -- easier than replicating that code here.
2813  */
2814 void
2815 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2816 {
2817         struct mbuf *copym;
2818         struct ip6_hdr *ip6;
2819
2820         copym = m_copy(m, 0, M_COPYALL);
2821         if (copym == NULL)
2822                 return;
2823
2824         /*
2825          * Make sure to deep-copy IPv6 header portion in case the data
2826          * is in an mbuf cluster, so that we can safely override the IPv6
2827          * header portion later.
2828          */
2829         if ((copym->m_flags & M_EXT) != 0 ||
2830             copym->m_len < sizeof(struct ip6_hdr)) {
2831                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
2832                 if (copym == NULL)
2833                         return;
2834         }
2835
2836 #ifdef DIAGNOSTIC
2837         if (copym->m_len < sizeof(*ip6)) {
2838                 m_freem(copym);
2839                 return;
2840         }
2841 #endif
2842
2843         ip6 = mtod(copym, struct ip6_hdr *);
2844         /*
2845          * clear embedded scope identifiers if necessary.
2846          * in6_clearscope will touch the addresses only when necessary.
2847          */
2848         in6_clearscope(&ip6->ip6_src);
2849         in6_clearscope(&ip6->ip6_dst);
2850
2851         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
2852 }
2853
2854 /*
2855  * Chop IPv6 header off from the payload.
2856  */
2857 static int
2858 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
2859 {
2860         struct mbuf *mh;
2861         struct ip6_hdr *ip6;
2862
2863         ip6 = mtod(m, struct ip6_hdr *);
2864         if (m->m_len > sizeof(*ip6)) {
2865                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
2866                 if (mh == 0) {
2867                         m_freem(m);
2868                         return ENOBUFS;
2869                 }
2870                 M_MOVE_PKTHDR(mh, m);
2871                 MH_ALIGN(mh, sizeof(*ip6));
2872                 m->m_len -= sizeof(*ip6);
2873                 m->m_data += sizeof(*ip6);
2874                 mh->m_next = m;
2875                 m = mh;
2876                 m->m_len = sizeof(*ip6);
2877                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
2878         }
2879         exthdrs->ip6e_ip6 = m;
2880         return 0;
2881 }
2882
2883 /*
2884  * Compute IPv6 extension header length.
2885  */
2886 int
2887 ip6_optlen(struct inpcb *in6p)
2888 {
2889         int len;
2890
2891         if (!in6p->in6p_outputopts)
2892                 return 0;
2893
2894         len = 0;
2895 #define elen(x) \
2896     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
2897
2898         len += elen(in6p->in6p_outputopts->ip6po_hbh);
2899         if (in6p->in6p_outputopts->ip6po_rthdr)
2900                 /* dest1 is valid with rthdr only */
2901                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
2902         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
2903         len += elen(in6p->in6p_outputopts->ip6po_dest2);
2904         return len;
2905 #undef elen
2906 }