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          * The outgoing interface must be in the zone of source and
 607          * destination addresses.  We should use ia_ifp to support the
 608          * case of sending packets to an address of our own.
 609          */
 610         if (ia != NULL && ia->ia_ifp)
 611                 origifp = ia->ia_ifp;
 612         else
 613                 origifp = ifp;
 614
 615         src0 = ip6->ip6_src;
 616         if (in6_setscope(&src0, origifp, &zone))
 617                 goto badscope;
 618         bzero(&src_sa, sizeof(src_sa));
 619         src_sa.sin6_family = AF_INET6;
 620         src_sa.sin6_len = sizeof(src_sa);
 621         src_sa.sin6_addr = ip6->ip6_src;
 622         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 623                 goto badscope;
 624
 625         dst0 = ip6->ip6_dst;
 626         if (in6_setscope(&dst0, origifp, &zone))
 627                 goto badscope;
 628         /* re-initialize to be sure */
 629         bzero(&dst_sa, sizeof(dst_sa));
 630         dst_sa.sin6_family = AF_INET6;
 631         dst_sa.sin6_len = sizeof(dst_sa);
 632         dst_sa.sin6_addr = ip6->ip6_dst;
 633         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 634                 goto badscope;
 635         }
 636
 637         /* scope check is done. */
 638         goto routefound;
 639
 640   badscope:
 641         V_ip6stat.ip6s_badscope++;
 642         in6_ifstat_inc(origifp, ifs6_out_discard);
 643         if (error == 0)
 644                 error = EHOSTUNREACH; /* XXX */
 645         goto bad;
 646
 647   routefound:
 648         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 649                 if (opt && opt->ip6po_nextroute.ro_rt) {
 650                         /*
 651                          * The nexthop is explicitly specified by the
 652                          * application.  We assume the next hop is an IPv6
 653                          * address.
 654                          */
 655                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 656                 }
 657                 else if ((rt->rt_flags & RTF_GATEWAY))
 658                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 659         }
 660
 661         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 662                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 663         } else {
 664                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 665                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 666                 /*
 667                  * Confirm that the outgoing interface supports multicast.
 668                  */
 669                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 670                         V_ip6stat.ip6s_noroute++;
 671                         in6_ifstat_inc(ifp, ifs6_out_discard);
 672                         error = ENETUNREACH;
 673                         goto bad;
 674                 }
 675                 if ((im6o == NULL && in6_mcast_loop) ||
 676                     (im6o && im6o->im6o_multicast_loop)) {
 677                         /*
 678                          * Loop back multicast datagram if not expressly
 679                          * forbidden to do so, even if we have not joined
 680                          * the address; protocols will filter it later,
 681                          * thus deferring a hash lookup and lock acquisition
 682                          * at the expense of an m_copym().
 683                          */
 684                         ip6_mloopback(ifp, m, dst);
 685                 } else {
 686                         /*
 687                          * If we are acting as a multicast router, perform
 688                          * multicast forwarding as if the packet had just
 689                          * arrived on the interface to which we are about
 690                          * to send.  The multicast forwarding function
 691                          * recursively calls this function, using the
 692                          * IPV6_FORWARDING flag to prevent infinite recursion.
 693                          *
 694                          * Multicasts that are looped back by ip6_mloopback(),
 695                          * above, will be forwarded by the ip6_input() routine,
 696                          * if necessary.
 697                          */
 698                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 699                                 /*
 700                                  * XXX: ip6_mforward expects that rcvif is NULL
 701                                  * when it is called from the originating path.
 702                                  * However, it is not always the case, since
 703                                  * some versions of MGETHDR() does not
 704                                  * initialize the field.
 705                                  */
 706                                 m->m_pkthdr.rcvif = NULL;
 707                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 708                                         m_freem(m);
 709                                         goto done;
 710                                 }
 711                         }
 712                 }
 713                 /*
 714                  * Multicasts with a hoplimit of zero may be looped back,
 715                  * above, but must not be transmitted on a network.
 716                  * Also, multicasts addressed to the loopback interface
 717                  * are not sent -- the above call to ip6_mloopback() will
 718                  * loop back a copy if this host actually belongs to the
 719                  * destination group on the loopback interface.
 720                  */
 721                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 722                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 723                         m_freem(m);
 724                         goto done;
 725                 }
 726         }
 727
 728         /*
 729          * Fill the outgoing inteface to tell the upper layer
 730          * to increment per-interface statistics.
 731          */
 732         if (ifpp)
 733                 *ifpp = ifp;
 734
 735         /* Determine path MTU. */
 736         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
 737             &alwaysfrag)) != 0)
 738                 goto bad;
 739
 740         /*
 741          * The caller of this function may specify to use the minimum MTU
 742          * in some cases.
 743          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 744          * setting.  The logic is a bit complicated; by default, unicast
 745          * packets will follow path MTU while multicast packets will be sent at
 746          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 747          * including unicast ones will be sent at the minimum MTU.  Multicast
 748          * packets will always be sent at the minimum MTU unless
 749          * IP6PO_MINMTU_DISABLE is explicitly specified.
 750          * See RFC 3542 for more details.
 751          */
 752         if (mtu > IPV6_MMTU) {
 753                 if ((flags & IPV6_MINMTU))
 754                         mtu = IPV6_MMTU;
 755                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 756                         mtu = IPV6_MMTU;
 757                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 758                          (opt == NULL ||
 759                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 760                         mtu = IPV6_MMTU;
 761                 }
 762         }
 763
 764         /*
 765          * clear embedded scope identifiers if necessary.
 766          * in6_clearscope will touch the addresses only when necessary.
 767          */
 768         in6_clearscope(&ip6->ip6_src);
 769         in6_clearscope(&ip6->ip6_dst);
 770
 771         /*
 772          * If the outgoing packet contains a hop-by-hop options header,
 773          * it must be examined and processed even by the source node.
 774          * (RFC 2460, section 4.)
 775          */
 776         if (exthdrs.ip6e_hbh) {
 777                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 778                 u_int32_t dummy; /* XXX unused */
 779                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 780
 781 #ifdef DIAGNOSTIC
 782                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 783                         panic("ip6e_hbh is not continuous");
 784 #endif
 785                 /*
 786                  *  XXX: if we have to send an ICMPv6 error to the sender,
 787                  *       we need the M_LOOP flag since icmp6_error() expects
 788                  *       the IPv6 and the hop-by-hop options header are
 789                  *       continuous unless the flag is set.
 790                  */
 791                 m->m_flags |= M_LOOP;
 792                 m->m_pkthdr.rcvif = ifp;
 793                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 794                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 795                     &dummy, &plen) < 0) {
 796                         /* m was already freed at this point */
 797                         error = EINVAL;/* better error? */
 798                         goto done;
 799                 }
 800                 m->m_flags &= ~M_LOOP; /* XXX */
 801                 m->m_pkthdr.rcvif = NULL;
 802         }
 803
 804         /* Jump over all PFIL processing if hooks are not active. */
 805         if (!PFIL_HOOKED(&inet6_pfil_hook))
 806                 goto passout;
 807
 808         odst = ip6->ip6_dst;
 809         /* Run through list of hooks for output packets. */
 810         error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 811         if (error != 0 || m == NULL)
 812                 goto done;
 813         ip6 = mtod(m, struct ip6_hdr *);
 814
 815         /* See if destination IP address was changed by packet filter. */
 816         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 817                 m->m_flags |= M_SKIP_FIREWALL;
 818                 /* If destination is now ourself drop to ip6_input(). */
 819                 if (in6_localaddr(&ip6->ip6_dst)) {
 820                         if (m->m_pkthdr.rcvif == NULL)
 821                                 m->m_pkthdr.rcvif = V_loif;
 822                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 823                                 m->m_pkthdr.csum_flags |=
 824                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 825                                 m->m_pkthdr.csum_data = 0xffff;
 826                         }
 827                         m->m_pkthdr.csum_flags |=
 828                             CSUM_IP_CHECKED | CSUM_IP_VALID;
 829                         error = netisr_queue(NETISR_IPV6, m);
 830                         goto done;
 831                 } else
 832                         goto again;     /* Redo the routing table lookup. */
 833         }
 834
 835         /* XXX: IPFIREWALL_FORWARD */
 836
 837 passout:
 838         /*
 839          * Send the packet to the outgoing interface.
 840          * If necessary, do IPv6 fragmentation before sending.
 841          *
 842          * the logic here is rather complex:
 843          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 844          * 1-a: send as is if tlen <= path mtu
 845          * 1-b: fragment if tlen > path mtu
 846          *
 847          * 2: if user asks us not to fragment (dontfrag == 1)
 848          * 2-a: send as is if tlen <= interface mtu
 849          * 2-b: error if tlen > interface mtu
 850          *
 851          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 852          *      always fragment
 853          *
 854          * 4: if dontfrag == 1 && alwaysfrag == 1
 855          *      error, as we cannot handle this conflicting request
 856          */
 857         tlen = m->m_pkthdr.len;
 858
 859         if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
 860                 dontfrag = 1;
 861         else
 862                 dontfrag = 0;
 863         if (dontfrag && alwaysfrag) {   /* case 4 */
 864                 /* conflicting request - can't transmit */
 865                 error = EMSGSIZE;
 866                 goto bad;
 867         }
 868         if (dontfrag && tlen > IN6_LINKMTU(ifp)) {      /* case 2-b */
 869                 /*
 870                  * Even if the DONTFRAG option is specified, we cannot send the
 871                  * packet when the data length is larger than the MTU of the
 872                  * outgoing interface.
 873                  * Notify the error by sending IPV6_PATHMTU ancillary data as
 874                  * well as returning an error code (the latter is not described
 875                  * in the API spec.)
 876                  */
 877                 u_int32_t mtu32;
 878                 struct ip6ctlparam ip6cp;
 879
 880                 mtu32 = (u_int32_t)mtu;
 881                 bzero(&ip6cp, sizeof(ip6cp));
 882                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
 883                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
 884                     (void *)&ip6cp);
 885
 886                 error = EMSGSIZE;
 887                 goto bad;
 888         }
 889
 890         /*
 891          * transmit packet without fragmentation
 892          */
 893         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 894                 struct in6_ifaddr *ia6;
 895
 896                 ip6 = mtod(m, struct ip6_hdr *);
 897                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 898                 if (ia6) {
 899                         /* Record statistics for this interface address. */
 900                         ia6->ia_ifa.if_opackets++;
 901                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
 902                         ifa_free(&ia6->ia_ifa);
 903                 }
 904                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
 905                 goto done;
 906         }
 907
 908         /*
 909          * try to fragment the packet.  case 1-b and 3
 910          */
 911         if (mtu < IPV6_MMTU) {
 912                 /* path MTU cannot be less than IPV6_MMTU */
 913                 error = EMSGSIZE;
 914                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 915                 goto bad;
 916         } else if (ip6->ip6_plen == 0) {
 917                 /* jumbo payload cannot be fragmented */
 918                 error = EMSGSIZE;
 919                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 920                 goto bad;
 921         } else {
 922                 struct mbuf **mnext, *m_frgpart;
 923                 struct ip6_frag *ip6f;
 924                 u_int32_t id = htonl(ip6_randomid());
 925                 u_char nextproto;
 926
 927                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
 928
 929                 /*
 930                  * Too large for the destination or interface;
 931                  * fragment if possible.
 932                  * Must be able to put at least 8 bytes per fragment.
 933                  */
 934                 hlen = unfragpartlen;
 935                 if (mtu > IPV6_MAXPACKET)
 936                         mtu = IPV6_MAXPACKET;
 937
 938                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 939                 if (len < 8) {
 940                         error = EMSGSIZE;
 941                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
 942                         goto bad;
 943                 }
 944
 945                 /*
 946                  * Verify that we have any chance at all of being able to queue
 947                  *      the packet or packet fragments
 948                  */
 949                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
 950                     < tlen  /* - hlen */)) {
 951                         error = ENOBUFS;
 952                         V_ip6stat.ip6s_odropped++;
 953                         goto bad;
 954                 }
 955
 956                 mnext = &m->m_nextpkt;
 957
 958                 /*
 959                  * Change the next header field of the last header in the
 960                  * unfragmentable part.
 961                  */
 962                 if (exthdrs.ip6e_rthdr) {
 963                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
 964                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
 965                 } else if (exthdrs.ip6e_dest1) {
 966                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
 967                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
 968                 } else if (exthdrs.ip6e_hbh) {
 969                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
 970                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
 971                 } else {
 972                         nextproto = ip6->ip6_nxt;
 973                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
 974                 }
 975
 976                 /*
 977                  * Loop through length of segment after first fragment,
 978                  * make new header and copy data of each part and link onto
 979                  * chain.
 980                  */
 981                 m0 = m;
 982                 for (off = hlen; off < tlen; off += len) {
 983                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
 984                         if (!m) {
 985                                 error = ENOBUFS;
 986                                 V_ip6stat.ip6s_odropped++;
 987                                 goto sendorfree;
 988                         }
 989                         m->m_pkthdr.rcvif = NULL;
 990                         m->m_flags = m0->m_flags & M_COPYFLAGS;
 991                         *mnext = m;
 992                         mnext = &m->m_nextpkt;
 993                         m->m_data += max_linkhdr;
 994                         mhip6 = mtod(m, struct ip6_hdr *);
 995                         *mhip6 = *ip6;
 996                         m->m_len = sizeof(*mhip6);
 997                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
 998                         if (error) {
 999                                 V_ip6stat.ip6s_odropped++;
1000                                 goto sendorfree;
1001                         }
1002                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1003                         if (off + len >= tlen)
1004                                 len = tlen - off;
1005                         else
1006                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1007                         mhip6->ip6_plen = htons((u_short)(len + hlen +
1008                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1009                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1010                                 error = ENOBUFS;
1011                                 V_ip6stat.ip6s_odropped++;
1012                                 goto sendorfree;
1013                         }
1014                         m_cat(m, m_frgpart);
1015                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1016                         m->m_pkthdr.rcvif = NULL;
1017                         ip6f->ip6f_reserved = 0;
1018                         ip6f->ip6f_ident = id;
1019                         ip6f->ip6f_nxt = nextproto;
1020                         V_ip6stat.ip6s_ofragments++;
1021                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1022                 }
1023
1024                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1025         }
1026
1027         /*
1028          * Remove leading garbages.
1029          */
1030 sendorfree:
1031         m = m0->m_nextpkt;
1032         m0->m_nextpkt = 0;
1033         m_freem(m0);
1034         for (m0 = m; m; m = m0) {
1035                 m0 = m->m_nextpkt;
1036                 m->m_nextpkt = 0;
1037                 if (error == 0) {
1038                         /* Record statistics for this interface address. */
1039                         if (ia) {
1040                                 ia->ia_ifa.if_opackets++;
1041                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1042                         }
1043                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1044                 } else
1045                         m_freem(m);
1046         }
1047
1048         if (error == 0)
1049                 V_ip6stat.ip6s_fragmented++;
1050
1051 done:
1052         if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
1053                 RTFREE(ro->ro_rt);
1054         } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
1055                 RTFREE(ro_pmtu->ro_rt);
1056         }
1057 #ifdef IPSEC
1058         if (sp != NULL)
1059                 KEY_FREESP(&sp);
1060 #endif
1061
1062         return (error);
1063
1064 freehdrs:
1065         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1066         m_freem(exthdrs.ip6e_dest1);
1067         m_freem(exthdrs.ip6e_rthdr);
1068         m_freem(exthdrs.ip6e_dest2);
1069         /* FALLTHROUGH */
1070 bad:
1071         if (m)
1072                 m_freem(m);
1073         goto done;
1074 }
1075
1076 static int
1077 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1078 {
1079         struct mbuf *m;
1080
1081         if (hlen > MCLBYTES)
1082                 return (ENOBUFS); /* XXX */
1083
1084         MGET(m, M_DONTWAIT, MT_DATA);
1085         if (!m)
1086                 return (ENOBUFS);
1087
1088         if (hlen > MLEN) {
1089                 MCLGET(m, M_DONTWAIT);
1090                 if ((m->m_flags & M_EXT) == 0) {
1091                         m_free(m);
1092                         return (ENOBUFS);
1093                 }
1094         }
1095         m->m_len = hlen;
1096         if (hdr)
1097                 bcopy(hdr, mtod(m, caddr_t), hlen);
1098
1099         *mp = m;
1100         return (0);
1101 }
1102
1103 /*
1104  * Insert jumbo payload option.
1105  */
1106 static int
1107 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1108 {
1109         struct mbuf *mopt;
1110         u_char *optbuf;
1111         u_int32_t v;
1112
1113 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1114
1115         /*
1116          * If there is no hop-by-hop options header, allocate new one.
1117          * If there is one but it doesn't have enough space to store the
1118          * jumbo payload option, allocate a cluster to store the whole options.
1119          * Otherwise, use it to store the options.
1120          */
1121         if (exthdrs->ip6e_hbh == 0) {
1122                 MGET(mopt, M_DONTWAIT, MT_DATA);
1123                 if (mopt == 0)
1124                         return (ENOBUFS);
1125                 mopt->m_len = JUMBOOPTLEN;
1126                 optbuf = mtod(mopt, u_char *);
1127                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1128                 exthdrs->ip6e_hbh = mopt;
1129         } else {
1130                 struct ip6_hbh *hbh;
1131
1132                 mopt = exthdrs->ip6e_hbh;
1133                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1134                         /*
1135                          * XXX assumption:
1136                          * - exthdrs->ip6e_hbh is not referenced from places
1137                          *   other than exthdrs.
1138                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1139                          */
1140                         int oldoptlen = mopt->m_len;
1141                         struct mbuf *n;
1142
1143                         /*
1144                          * XXX: give up if the whole (new) hbh header does
1145                          * not fit even in an mbuf cluster.
1146                          */
1147                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1148                                 return (ENOBUFS);
1149
1150                         /*
1151                          * As a consequence, we must always prepare a cluster
1152                          * at this point.
1153                          */
1154                         MGET(n, M_DONTWAIT, MT_DATA);
1155                         if (n) {
1156                                 MCLGET(n, M_DONTWAIT);
1157                                 if ((n->m_flags & M_EXT) == 0) {
1158                                         m_freem(n);
1159                                         n = NULL;
1160                                 }
1161                         }
1162                         if (!n)
1163                                 return (ENOBUFS);
1164                         n->m_len = oldoptlen + JUMBOOPTLEN;
1165                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1166                             oldoptlen);
1167                         optbuf = mtod(n, caddr_t) + oldoptlen;
1168                         m_freem(mopt);
1169                         mopt = exthdrs->ip6e_hbh = n;
1170                 } else {
1171                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1172                         mopt->m_len += JUMBOOPTLEN;
1173                 }
1174                 optbuf[0] = IP6OPT_PADN;
1175                 optbuf[1] = 1;
1176
1177                 /*
1178                  * Adjust the header length according to the pad and
1179                  * the jumbo payload option.
1180                  */
1181                 hbh = mtod(mopt, struct ip6_hbh *);
1182                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1183         }
1184
1185         /* fill in the option. */
1186         optbuf[2] = IP6OPT_JUMBO;
1187         optbuf[3] = 4;
1188         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1189         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1190
1191         /* finally, adjust the packet header length */
1192         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1193
1194         return (0);
1195 #undef JUMBOOPTLEN
1196 }
1197
1198 /*
1199  * Insert fragment header and copy unfragmentable header portions.
1200  */
1201 static int
1202 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1203     struct ip6_frag **frghdrp)
1204 {
1205         struct mbuf *n, *mlast;
1206
1207         if (hlen > sizeof(struct ip6_hdr)) {
1208                 n = m_copym(m0, sizeof(struct ip6_hdr),
1209                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
1210                 if (n == 0)
1211                         return (ENOBUFS);
1212                 m->m_next = n;
1213         } else
1214                 n = m;
1215
1216         /* Search for the last mbuf of unfragmentable part. */
1217         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1218                 ;
1219
1220         if ((mlast->m_flags & M_EXT) == 0 &&
1221             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1222                 /* use the trailing space of the last mbuf for the fragment hdr */
1223                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1224                     mlast->m_len);
1225                 mlast->m_len += sizeof(struct ip6_frag);
1226                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1227         } else {
1228                 /* allocate a new mbuf for the fragment header */
1229                 struct mbuf *mfrg;
1230
1231                 MGET(mfrg, M_DONTWAIT, MT_DATA);
1232                 if (mfrg == 0)
1233                         return (ENOBUFS);
1234                 mfrg->m_len = sizeof(struct ip6_frag);
1235                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1236                 mlast->m_next = mfrg;
1237         }
1238
1239         return (0);
1240 }
1241
1242 static int
1243 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1244     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1245     int *alwaysfragp)
1246 {
1247         u_int32_t mtu = 0;
1248         int alwaysfrag = 0;
1249         int error = 0;
1250
1251         if (ro_pmtu != ro) {
1252                 /* The first hop and the final destination may differ. */
1253                 struct sockaddr_in6 *sa6_dst =
1254                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1255                 if (ro_pmtu->ro_rt &&
1256                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1257                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1258                         RTFREE(ro_pmtu->ro_rt);
1259                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
1260                 }
1261                 if (ro_pmtu->ro_rt == NULL) {
1262                         bzero(sa6_dst, sizeof(*sa6_dst));
1263                         sa6_dst->sin6_family = AF_INET6;
1264                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1265                         sa6_dst->sin6_addr = *dst;
1266
1267                         rtalloc((struct route *)ro_pmtu);
1268                 }
1269         }
1270         if (ro_pmtu->ro_rt) {
1271                 u_int32_t ifmtu;
1272                 struct in_conninfo inc;
1273
1274                 bzero(&inc, sizeof(inc));
1275                 inc.inc_flags |= INC_ISIPV6;
1276                 inc.inc6_faddr = *dst;
1277
1278                 if (ifp == NULL)
1279                         ifp = ro_pmtu->ro_rt->rt_ifp;
1280                 ifmtu = IN6_LINKMTU(ifp);
1281                 mtu = tcp_hc_getmtu(&inc);
1282                 if (mtu)
1283                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
1284                 else
1285                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1286                 if (mtu == 0)
1287                         mtu = ifmtu;
1288                 else if (mtu < IPV6_MMTU) {
1289                         /*
1290                          * RFC2460 section 5, last paragraph:
1291                          * if we record ICMPv6 too big message with
1292                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1293                          * or smaller, with framgent header attached.
1294                          * (fragment header is needed regardless from the
1295                          * packet size, for translators to identify packets)
1296                          */
1297                         alwaysfrag = 1;
1298                         mtu = IPV6_MMTU;
1299                 } else if (mtu > ifmtu) {
1300                         /*
1301                          * The MTU on the route is larger than the MTU on
1302                          * the interface!  This shouldn't happen, unless the
1303                          * MTU of the interface has been changed after the
1304                          * interface was brought up.  Change the MTU in the
1305                          * route to match the interface MTU (as long as the
1306                          * field isn't locked).
1307                          */
1308                         mtu = ifmtu;
1309                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1310                 }
1311         } else if (ifp) {
1312                 mtu = IN6_LINKMTU(ifp);
1313         } else
1314                 error = EHOSTUNREACH; /* XXX */
1315
1316         *mtup = mtu;
1317         if (alwaysfragp)
1318                 *alwaysfragp = alwaysfrag;
1319         return (error);
1320 }
1321
1322 /*
1323  * IP6 socket option processing.
1324  */
1325 int
1326 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1327 {
1328         int optdatalen, uproto;
1329         void *optdata;
1330         struct inpcb *in6p = sotoinpcb(so);
1331         int error, optval;
1332         int level, op, optname;
1333         int optlen;
1334         struct thread *td;
1335
1336         level = sopt->sopt_level;
1337         op = sopt->sopt_dir;
1338         optname = sopt->sopt_name;
1339         optlen = sopt->sopt_valsize;
1340         td = sopt->sopt_td;
1341         error = 0;
1342         optval = 0;
1343         uproto = (int)so->so_proto->pr_protocol;
1344
1345         if (level == IPPROTO_IPV6) {
1346                 switch (op) {
1347
1348                 case SOPT_SET:
1349                         switch (optname) {
1350                         case IPV6_2292PKTOPTIONS:
1351 #ifdef IPV6_PKTOPTIONS
1352                         case IPV6_PKTOPTIONS:
1353 #endif
1354                         {
1355                                 struct mbuf *m;
1356
1357                                 error = soopt_getm(sopt, &m); /* XXX */
1358                                 if (error != 0)
1359                                         break;
1360                                 error = soopt_mcopyin(sopt, m); /* XXX */
1361                                 if (error != 0)
1362                                         break;
1363                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1364                                                     m, so, sopt);
1365                                 m_freem(m); /* XXX */
1366                                 break;
1367                         }
1368
1369                         /*
1370                          * Use of some Hop-by-Hop options or some
1371                          * Destination options, might require special
1372                          * privilege.  That is, normal applications
1373                          * (without special privilege) might be forbidden
1374                          * from setting certain options in outgoing packets,
1375                          * and might never see certain options in received
1376                          * packets. [RFC 2292 Section 6]
1377                          * KAME specific note:
1378                          *  KAME prevents non-privileged users from sending or
1379                          *  receiving ANY hbh/dst options in order to avoid
1380                          *  overhead of parsing options in the kernel.
1381                          */
1382                         case IPV6_RECVHOPOPTS:
1383                         case IPV6_RECVDSTOPTS:
1384                         case IPV6_RECVRTHDRDSTOPTS:
1385                                 if (td != NULL) {
1386                                         error = priv_check(td,
1387                                             PRIV_NETINET_SETHDROPTS);
1388                                         if (error)
1389                                                 break;
1390                                 }
1391                                 /* FALLTHROUGH */
1392                         case IPV6_UNICAST_HOPS:
1393                         case IPV6_HOPLIMIT:
1394                         case IPV6_FAITH:
1395
1396                         case IPV6_RECVPKTINFO:
1397                         case IPV6_RECVHOPLIMIT:
1398                         case IPV6_RECVRTHDR:
1399                         case IPV6_RECVPATHMTU:
1400                         case IPV6_RECVTCLASS:
1401                         case IPV6_V6ONLY:
1402                         case IPV6_AUTOFLOWLABEL:
1403                         case IPV6_BINDANY:
1404                                 if (optname == IPV6_BINDANY && td != NULL) {
1405                                         error = priv_check(td,
1406                                             PRIV_NETINET_BINDANY);
1407                                         if (error)
1408                                                 break;
1409                                 }
1410
1411                                 if (optlen != sizeof(int)) {
1412                                         error = EINVAL;
1413                                         break;
1414                                 }
1415                                 error = sooptcopyin(sopt, &optval,
1416                                         sizeof optval, sizeof optval);
1417                                 if (error)
1418                                         break;
1419                                 switch (optname) {
1420
1421                                 case IPV6_UNICAST_HOPS:
1422                                         if (optval < -1 || optval >= 256)
1423                                                 error = EINVAL;
1424                                         else {
1425                                                 /* -1 = kernel default */
1426                                                 in6p->in6p_hops = optval;
1427                                                 if ((in6p->inp_vflag &
1428                                                      INP_IPV4) != 0)
1429                                                         in6p->inp_ip_ttl = optval;
1430                                         }
1431                                         break;
1432 #define OPTSET(bit) \
1433 do { \
1434         if (optval) \
1435                 in6p->inp_flags |= (bit); \
1436         else \
1437                 in6p->inp_flags &= ~(bit); \
1438 } while (/*CONSTCOND*/ 0)
1439 #define OPTSET2292(bit) \
1440 do { \
1441         in6p->inp_flags |= IN6P_RFC2292; \
1442         if (optval) \
1443                 in6p->inp_flags |= (bit); \
1444         else \
1445                 in6p->inp_flags &= ~(bit); \
1446 } while (/*CONSTCOND*/ 0)
1447 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1448
1449                                 case IPV6_RECVPKTINFO:
1450                                         /* cannot mix with RFC2292 */
1451                                         if (OPTBIT(IN6P_RFC2292)) {
1452                                                 error = EINVAL;
1453                                                 break;
1454                                         }
1455                                         OPTSET(IN6P_PKTINFO);
1456                                         break;
1457
1458                                 case IPV6_HOPLIMIT:
1459                                 {
1460                                         struct ip6_pktopts **optp;
1461
1462                                         /* cannot mix with RFC2292 */
1463                                         if (OPTBIT(IN6P_RFC2292)) {
1464                                                 error = EINVAL;
1465                                                 break;
1466                                         }
1467                                         optp = &in6p->in6p_outputopts;
1468                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1469                                             (u_char *)&optval, sizeof(optval),
1470                                             optp, (td != NULL) ? td->td_ucred :
1471                                             NULL, uproto);
1472                                         break;
1473                                 }
1474
1475                                 case IPV6_RECVHOPLIMIT:
1476                                         /* cannot mix with RFC2292 */
1477                                         if (OPTBIT(IN6P_RFC2292)) {
1478                                                 error = EINVAL;
1479                                                 break;
1480                                         }
1481                                         OPTSET(IN6P_HOPLIMIT);
1482                                         break;
1483
1484                                 case IPV6_RECVHOPOPTS:
1485                                         /* cannot mix with RFC2292 */
1486                                         if (OPTBIT(IN6P_RFC2292)) {
1487                                                 error = EINVAL;
1488                                                 break;
1489                                         }
1490                                         OPTSET(IN6P_HOPOPTS);
1491                                         break;
1492
1493                                 case IPV6_RECVDSTOPTS:
1494                                         /* cannot mix with RFC2292 */
1495                                         if (OPTBIT(IN6P_RFC2292)) {
1496                                                 error = EINVAL;
1497                                                 break;
1498                                         }
1499                                         OPTSET(IN6P_DSTOPTS);
1500                                         break;
1501
1502                                 case IPV6_RECVRTHDRDSTOPTS:
1503                                         /* cannot mix with RFC2292 */
1504                                         if (OPTBIT(IN6P_RFC2292)) {
1505                                                 error = EINVAL;
1506                                                 break;
1507                                         }
1508                                         OPTSET(IN6P_RTHDRDSTOPTS);
1509                                         break;
1510
1511                                 case IPV6_RECVRTHDR:
1512                                         /* cannot mix with RFC2292 */
1513                                         if (OPTBIT(IN6P_RFC2292)) {
1514                                                 error = EINVAL;
1515                                                 break;
1516                                         }
1517                                         OPTSET(IN6P_RTHDR);
1518                                         break;
1519
1520                                 case IPV6_FAITH:
1521                                         OPTSET(INP_FAITH);
1522                                         break;
1523
1524                                 case IPV6_RECVPATHMTU:
1525                                         /*
1526                                          * We ignore this option for TCP
1527                                          * sockets.
1528                                          * (RFC3542 leaves this case
1529                                          * unspecified.)
1530                                          */
1531                                         if (uproto != IPPROTO_TCP)
1532                                                 OPTSET(IN6P_MTU);
1533                                         break;
1534
1535                                 case IPV6_V6ONLY:
1536                                         /*
1537                                          * make setsockopt(IPV6_V6ONLY)
1538                                          * available only prior to bind(2).
1539                                          * see ipng mailing list, Jun 22 2001.
1540                                          */
1541                                         if (in6p->inp_lport ||
1542                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1543                                                 error = EINVAL;
1544                                                 break;
1545                                         }
1546                                         OPTSET(IN6P_IPV6_V6ONLY);
1547                                         if (optval)
1548                                                 in6p->inp_vflag &= ~INP_IPV4;
1549                                         else
1550                                                 in6p->inp_vflag |= INP_IPV4;
1551                                         break;
1552                                 case IPV6_RECVTCLASS:
1553                                         /* cannot mix with RFC2292 XXX */
1554                                         if (OPTBIT(IN6P_RFC2292)) {
1555                                                 error = EINVAL;
1556                                                 break;
1557                                         }
1558                                         OPTSET(IN6P_TCLASS);
1559                                         break;
1560                                 case IPV6_AUTOFLOWLABEL:
1561                                         OPTSET(IN6P_AUTOFLOWLABEL);
1562                                         break;
1563
1564                                 case IPV6_BINDANY:
1565                                         OPTSET(INP_BINDANY);
1566                                         break;
1567                                 }
1568                                 break;
1569
1570                         case IPV6_TCLASS:
1571                         case IPV6_DONTFRAG:
1572                         case IPV6_USE_MIN_MTU:
1573                         case IPV6_PREFER_TEMPADDR:
1574                                 if (optlen != sizeof(optval)) {
1575                                         error = EINVAL;
1576                                         break;
1577                                 }
1578                                 error = sooptcopyin(sopt, &optval,
1579                                         sizeof optval, sizeof optval);
1580                                 if (error)
1581                                         break;
1582                                 {
1583                                         struct ip6_pktopts **optp;
1584                                         optp = &in6p->in6p_outputopts;
1585                                         error = ip6_pcbopt(optname,
1586                                             (u_char *)&optval, sizeof(optval),
1587                                             optp, (td != NULL) ? td->td_ucred :
1588                                             NULL, uproto);
1589                                         break;
1590                                 }
1591
1592                         case IPV6_2292PKTINFO:
1593                         case IPV6_2292HOPLIMIT:
1594                         case IPV6_2292HOPOPTS:
1595                         case IPV6_2292DSTOPTS:
1596                         case IPV6_2292RTHDR:
1597                                 /* RFC 2292 */
1598                                 if (optlen != sizeof(int)) {
1599                                         error = EINVAL;
1600                                         break;
1601                                 }
1602                                 error = sooptcopyin(sopt, &optval,
1603                                         sizeof optval, sizeof optval);
1604                                 if (error)
1605                                         break;
1606                                 switch (optname) {
1607                                 case IPV6_2292PKTINFO:
1608                                         OPTSET2292(IN6P_PKTINFO);
1609                                         break;
1610                                 case IPV6_2292HOPLIMIT:
1611                                         OPTSET2292(IN6P_HOPLIMIT);
1612                                         break;
1613                                 case IPV6_2292HOPOPTS:
1614                                         /*
1615                                          * Check super-user privilege.
1616                                          * See comments for IPV6_RECVHOPOPTS.
1617                                          */
1618                                         if (td != NULL) {
1619                                                 error = priv_check(td,
1620                                                     PRIV_NETINET_SETHDROPTS);
1621                                                 if (error)
1622                                                         return (error);
1623                                         }
1624                                         OPTSET2292(IN6P_HOPOPTS);
1625                                         break;
1626                                 case IPV6_2292DSTOPTS:
1627                                         if (td != NULL) {
1628                                                 error = priv_check(td,
1629                                                     PRIV_NETINET_SETHDROPTS);
1630                                                 if (error)
1631                                                         return (error);
1632                                         }
1633                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1634                                         break;
1635                                 case IPV6_2292RTHDR:
1636                                         OPTSET2292(IN6P_RTHDR);
1637                                         break;
1638                                 }
1639                                 break;
1640                         case IPV6_PKTINFO:
1641                         case IPV6_HOPOPTS:
1642                         case IPV6_RTHDR:
1643                         case IPV6_DSTOPTS:
1644                         case IPV6_RTHDRDSTOPTS:
1645                         case IPV6_NEXTHOP:
1646                         {
1647                                 /* new advanced API (RFC3542) */
1648                                 u_char *optbuf;
1649                                 u_char optbuf_storage[MCLBYTES];
1650                                 int optlen;
1651                                 struct ip6_pktopts **optp;
1652
1653                                 /* cannot mix with RFC2292 */
1654                                 if (OPTBIT(IN6P_RFC2292)) {
1655                                         error = EINVAL;
1656                                         break;
1657                                 }
1658
1659                                 /*
1660                                  * We only ensure valsize is not too large
1661                                  * here.  Further validation will be done
1662                                  * later.
1663                                  */
1664                                 error = sooptcopyin(sopt, optbuf_storage,
1665                                     sizeof(optbuf_storage), 0);
1666                                 if (error)
1667                                         break;
1668                                 optlen = sopt->sopt_valsize;
1669                                 optbuf = optbuf_storage;
1670                                 optp = &in6p->in6p_outputopts;
1671                                 error = ip6_pcbopt(optname, optbuf, optlen,
1672                                     optp, (td != NULL) ? td->td_ucred : NULL,
1673                                     uproto);
1674                                 break;
1675                         }
1676 #undef OPTSET
1677
1678                         case IPV6_MULTICAST_IF:
1679                         case IPV6_MULTICAST_HOPS:
1680                         case IPV6_MULTICAST_LOOP:
1681                         case IPV6_JOIN_GROUP:
1682                         case IPV6_LEAVE_GROUP:
1683                         case IPV6_MSFILTER:
1684                         case MCAST_BLOCK_SOURCE:
1685                         case MCAST_UNBLOCK_SOURCE:
1686                         case MCAST_JOIN_GROUP:
1687                         case MCAST_LEAVE_GROUP:
1688                         case MCAST_JOIN_SOURCE_GROUP:
1689                         case MCAST_LEAVE_SOURCE_GROUP:
1690                                 error = ip6_setmoptions(in6p, sopt);
1691                                 break;
1692
1693                         case IPV6_PORTRANGE:
1694                                 error = sooptcopyin(sopt, &optval,
1695                                     sizeof optval, sizeof optval);
1696                                 if (error)
1697                                         break;
1698
1699                                 switch (optval) {
1700                                 case IPV6_PORTRANGE_DEFAULT:
1701                                         in6p->inp_flags &= ~(INP_LOWPORT);
1702                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1703                                         break;
1704
1705                                 case IPV6_PORTRANGE_HIGH:
1706                                         in6p->inp_flags &= ~(INP_LOWPORT);
1707                                         in6p->inp_flags |= INP_HIGHPORT;
1708                                         break;
1709
1710                                 case IPV6_PORTRANGE_LOW:
1711                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1712                                         in6p->inp_flags |= INP_LOWPORT;
1713                                         break;
1714
1715                                 default:
1716                                         error = EINVAL;
1717                                         break;
1718                                 }
1719                                 break;
1720
1721 #ifdef IPSEC
1722                         case IPV6_IPSEC_POLICY:
1723                         {
1724                                 caddr_t req;
1725                                 struct mbuf *m;
1726
1727                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1728                                         break;
1729                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1730                                         break;
1731                                 req = mtod(m, caddr_t);
1732                                 error = ipsec_set_policy(in6p, optname, req,
1733                                     m->m_len, (sopt->sopt_td != NULL) ?
1734                                     sopt->sopt_td->td_ucred : NULL);
1735                                 m_freem(m);
1736                                 break;
1737                         }
1738 #endif /* IPSEC */
1739
1740                         default:
1741                                 error = ENOPROTOOPT;
1742                                 break;
1743                         }
1744                         break;
1745
1746                 case SOPT_GET:
1747                         switch (optname) {
1748
1749                         case IPV6_2292PKTOPTIONS:
1750 #ifdef IPV6_PKTOPTIONS
1751                         case IPV6_PKTOPTIONS:
1752 #endif
1753                                 /*
1754                                  * RFC3542 (effectively) deprecated the
1755                                  * semantics of the 2292-style pktoptions.
1756                                  * Since it was not reliable in nature (i.e.,
1757                                  * applications had to expect the lack of some
1758                                  * information after all), it would make sense
1759                                  * to simplify this part by always returning
1760                                  * empty data.
1761                                  */
1762                                 sopt->sopt_valsize = 0;
1763                                 break;
1764
1765                         case IPV6_RECVHOPOPTS:
1766                         case IPV6_RECVDSTOPTS:
1767                         case IPV6_RECVRTHDRDSTOPTS:
1768                         case IPV6_UNICAST_HOPS:
1769                         case IPV6_RECVPKTINFO:
1770                         case IPV6_RECVHOPLIMIT:
1771                         case IPV6_RECVRTHDR:
1772                         case IPV6_RECVPATHMTU:
1773
1774                         case IPV6_FAITH:
1775                         case IPV6_V6ONLY:
1776                         case IPV6_PORTRANGE:
1777                         case IPV6_RECVTCLASS:
1778                         case IPV6_AUTOFLOWLABEL:
1779                                 switch (optname) {
1780
1781                                 case IPV6_RECVHOPOPTS:
1782                                         optval = OPTBIT(IN6P_HOPOPTS);
1783                                         break;
1784
1785                                 case IPV6_RECVDSTOPTS:
1786                                         optval = OPTBIT(IN6P_DSTOPTS);
1787                                         break;
1788
1789                                 case IPV6_RECVRTHDRDSTOPTS:
1790                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1791                                         break;
1792
1793                                 case IPV6_UNICAST_HOPS:
1794                                         optval = in6p->in6p_hops;
1795                                         break;
1796
1797                                 case IPV6_RECVPKTINFO:
1798                                         optval = OPTBIT(IN6P_PKTINFO);
1799                                         break;
1800
1801                                 case IPV6_RECVHOPLIMIT:
1802                                         optval = OPTBIT(IN6P_HOPLIMIT);
1803                                         break;
1804
1805                                 case IPV6_RECVRTHDR:
1806                                         optval = OPTBIT(IN6P_RTHDR);
1807                                         break;
1808
1809                                 case IPV6_RECVPATHMTU:
1810                                         optval = OPTBIT(IN6P_MTU);
1811                                         break;
1812
1813                                 case IPV6_FAITH:
1814                                         optval = OPTBIT(INP_FAITH);
1815                                         break;
1816
1817                                 case IPV6_V6ONLY:
1818                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1819                                         break;
1820
1821                                 case IPV6_PORTRANGE:
1822                                     {
1823                                         int flags;
1824                                         flags = in6p->inp_flags;
1825                                         if (flags & INP_HIGHPORT)
1826                                                 optval = IPV6_PORTRANGE_HIGH;
1827                                         else if (flags & INP_LOWPORT)
1828                                                 optval = IPV6_PORTRANGE_LOW;
1829                                         else
1830                                                 optval = 0;
1831                                         break;
1832                                     }
1833                                 case IPV6_RECVTCLASS:
1834                                         optval = OPTBIT(IN6P_TCLASS);
1835                                         break;
1836
1837                                 case IPV6_AUTOFLOWLABEL:
1838                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1839                                         break;
1840
1841                                 case IPV6_BINDANY:
1842                                         optval = OPTBIT(INP_BINDANY);
1843                                         break;
1844                                 }
1845                                 if (error)
1846                                         break;
1847                                 error = sooptcopyout(sopt, &optval,
1848                                         sizeof optval);
1849                                 break;
1850
1851                         case IPV6_PATHMTU:
1852                         {
1853                                 u_long pmtu = 0;
1854                                 struct ip6_mtuinfo mtuinfo;
1855                                 struct route_in6 sro;
1856
1857                                 bzero(&sro, sizeof(sro));
1858
1859                                 if (!(so->so_state & SS_ISCONNECTED))
1860                                         return (ENOTCONN);
1861                                 /*
1862                                  * XXX: we dot not consider the case of source
1863                                  * routing, or optional information to specify
1864                                  * the outgoing interface.
1865                                  */
1866                                 error = ip6_getpmtu(&sro, NULL, NULL,
1867                                     &in6p->in6p_faddr, &pmtu, NULL);
1868                                 if (sro.ro_rt)
1869                                         RTFREE(sro.ro_rt);
1870                                 if (error)
1871                                         break;
1872                                 if (pmtu > IPV6_MAXPACKET)
1873                                         pmtu = IPV6_MAXPACKET;
1874
1875                                 bzero(&mtuinfo, sizeof(mtuinfo));
1876                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1877                                 optdata = (void *)&mtuinfo;
1878                                 optdatalen = sizeof(mtuinfo);
1879                                 error = sooptcopyout(sopt, optdata,
1880                                     optdatalen);
1881                                 break;
1882                         }
1883
1884                         case IPV6_2292PKTINFO:
1885                         case IPV6_2292HOPLIMIT:
1886                         case IPV6_2292HOPOPTS:
1887                         case IPV6_2292RTHDR:
1888                         case IPV6_2292DSTOPTS:
1889                                 switch (optname) {
1890                                 case IPV6_2292PKTINFO:
1891                                         optval = OPTBIT(IN6P_PKTINFO);
1892                                         break;
1893                                 case IPV6_2292HOPLIMIT:
1894                                         optval = OPTBIT(IN6P_HOPLIMIT);
1895                                         break;
1896                                 case IPV6_2292HOPOPTS:
1897                                         optval = OPTBIT(IN6P_HOPOPTS);
1898                                         break;
1899                                 case IPV6_2292RTHDR:
1900                                         optval = OPTBIT(IN6P_RTHDR);
1901                                         break;
1902                                 case IPV6_2292DSTOPTS:
1903                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1904                                         break;
1905                                 }
1906                                 error = sooptcopyout(sopt, &optval,
1907                                     sizeof optval);
1908                                 break;
1909                         case IPV6_PKTINFO:
1910                         case IPV6_HOPOPTS:
1911                         case IPV6_RTHDR:
1912                         case IPV6_DSTOPTS:
1913                         case IPV6_RTHDRDSTOPTS:
1914                         case IPV6_NEXTHOP:
1915                         case IPV6_TCLASS:
1916                         case IPV6_DONTFRAG:
1917                         case IPV6_USE_MIN_MTU:
1918                         case IPV6_PREFER_TEMPADDR:
1919                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
1920                                     optname, sopt);
1921                                 break;
1922
1923                         case IPV6_MULTICAST_IF:
1924                         case IPV6_MULTICAST_HOPS:
1925                         case IPV6_MULTICAST_LOOP:
1926                         case IPV6_MSFILTER:
1927                                 error = ip6_getmoptions(in6p, sopt);
1928                                 break;
1929
1930 #ifdef IPSEC
1931                         case IPV6_IPSEC_POLICY:
1932                           {
1933                                 caddr_t req = NULL;
1934                                 size_t len = 0;
1935                                 struct mbuf *m = NULL;
1936                                 struct mbuf **mp = &m;
1937                                 size_t ovalsize = sopt->sopt_valsize;
1938                                 caddr_t oval = (caddr_t)sopt->sopt_val;
1939
1940                                 error = soopt_getm(sopt, &m); /* XXX */
1941                                 if (error != 0)
1942                                         break;
1943                                 error = soopt_mcopyin(sopt, m); /* XXX */
1944                                 if (error != 0)
1945                                         break;
1946                                 sopt->sopt_valsize = ovalsize;
1947                                 sopt->sopt_val = oval;
1948                                 if (m) {
1949                                         req = mtod(m, caddr_t);
1950                                         len = m->m_len;
1951                                 }
1952                                 error = ipsec_get_policy(in6p, req, len, mp);
1953                                 if (error == 0)
1954                                         error = soopt_mcopyout(sopt, m); /* XXX */
1955                                 if (error == 0 && m)
1956                                         m_freem(m);
1957                                 break;
1958                           }
1959 #endif /* IPSEC */
1960
1961                         default:
1962                                 error = ENOPROTOOPT;
1963                                 break;
1964                         }
1965                         break;
1966                 }
1967         } else {                /* level != IPPROTO_IPV6 */
1968                 error = EINVAL;
1969         }
1970         return (error);
1971 }
1972
1973 int
1974 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
1975 {
1976         int error = 0, optval, optlen;
1977         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
1978         struct inpcb *in6p = sotoinpcb(so);
1979         int level, op, optname;
1980
1981         level = sopt->sopt_level;
1982         op = sopt->sopt_dir;
1983         optname = sopt->sopt_name;
1984         optlen = sopt->sopt_valsize;
1985
1986         if (level != IPPROTO_IPV6) {
1987                 return (EINVAL);
1988         }
1989
1990         switch (optname) {
1991         case IPV6_CHECKSUM:
1992                 /*
1993                  * For ICMPv6 sockets, no modification allowed for checksum
1994                  * offset, permit "no change" values to help existing apps.
1995                  *
1996                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
1997                  * for an ICMPv6 socket will fail."
1998                  * The current behavior does not meet RFC3542.
1999                  */
2000                 switch (op) {
2001                 case SOPT_SET:
2002                         if (optlen != sizeof(int)) {
2003                                 error = EINVAL;
2004                                 break;
2005                         }
2006                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2007                                             sizeof(optval));
2008                         if (error)
2009                                 break;
2010                         if ((optval % 2) != 0) {
2011                                 /* the API assumes even offset values */
2012                                 error = EINVAL;
2013                         } else if (so->so_proto->pr_protocol ==
2014                             IPPROTO_ICMPV6) {
2015                                 if (optval != icmp6off)
2016                                         error = EINVAL;
2017                         } else
2018                                 in6p->in6p_cksum = optval;
2019                         break;
2020
2021                 case SOPT_GET:
2022                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2023                                 optval = icmp6off;
2024                         else
2025                                 optval = in6p->in6p_cksum;
2026
2027                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2028                         break;
2029
2030                 default:
2031                         error = EINVAL;
2032                         break;
2033                 }
2034                 break;
2035
2036         default:
2037                 error = ENOPROTOOPT;
2038                 break;
2039         }
2040
2041         return (error);
2042 }
2043
2044 /*
2045  * Set up IP6 options in pcb for insertion in output packets or
2046  * specifying behavior of outgoing packets.
2047  */
2048 static int
2049 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2050     struct socket *so, struct sockopt *sopt)
2051 {
2052         struct ip6_pktopts *opt = *pktopt;
2053         int error = 0;
2054         struct thread *td = sopt->sopt_td;
2055
2056         /* turn off any old options. */
2057         if (opt) {
2058 #ifdef DIAGNOSTIC
2059                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2060                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2061                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2062                         printf("ip6_pcbopts: all specified options are cleared.\n");
2063 #endif
2064                 ip6_clearpktopts(opt, -1);
2065         } else
2066                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2067         *pktopt = NULL;
2068
2069         if (!m || m->m_len == 0) {
2070                 /*
2071                  * Only turning off any previous options, regardless of
2072                  * whether the opt is just created or given.
2073                  */
2074                 free(opt, M_IP6OPT);
2075                 return (0);
2076         }
2077
2078         /*  set options specified by user. */
2079         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2080             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2081                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2082                 free(opt, M_IP6OPT);
2083                 return (error);
2084         }
2085         *pktopt = opt;
2086         return (0);
2087 }
2088
2089 /*
2090  * initialize ip6_pktopts.  beware that there are non-zero default values in
2091  * the struct.
2092  */
2093 void
2094 ip6_initpktopts(struct ip6_pktopts *opt)
2095 {
2096
2097         bzero(opt, sizeof(*opt));
2098         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2099         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2100         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2101         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2102 }
2103
2104 static int
2105 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2106     struct ucred *cred, int uproto)
2107 {
2108         struct ip6_pktopts *opt;
2109
2110         if (*pktopt == NULL) {
2111                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2112                     M_WAITOK);
2113                 ip6_initpktopts(*pktopt);
2114         }
2115         opt = *pktopt;
2116
2117         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2118 }
2119
2120 static int
2121 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2122 {
2123         void *optdata = NULL;
2124         int optdatalen = 0;
2125         struct ip6_ext *ip6e;
2126         int error = 0;
2127         struct in6_pktinfo null_pktinfo;
2128         int deftclass = 0, on;
2129         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2130         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2131
2132         switch (optname) {
2133         case IPV6_PKTINFO:
2134                 if (pktopt && pktopt->ip6po_pktinfo)
2135                         optdata = (void *)pktopt->ip6po_pktinfo;
2136                 else {
2137                         /* XXX: we don't have to do this every time... */
2138                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2139                         optdata = (void *)&null_pktinfo;
2140                 }
2141                 optdatalen = sizeof(struct in6_pktinfo);
2142                 break;
2143         case IPV6_TCLASS:
2144                 if (pktopt && pktopt->ip6po_tclass >= 0)
2145                         optdata = (void *)&pktopt->ip6po_tclass;
2146                 else
2147                         optdata = (void *)&deftclass;
2148                 optdatalen = sizeof(int);
2149                 break;
2150         case IPV6_HOPOPTS:
2151                 if (pktopt && pktopt->ip6po_hbh) {
2152                         optdata = (void *)pktopt->ip6po_hbh;
2153                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2154                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2155                 }
2156                 break;
2157         case IPV6_RTHDR:
2158                 if (pktopt && pktopt->ip6po_rthdr) {
2159                         optdata = (void *)pktopt->ip6po_rthdr;
2160                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2161                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2162                 }
2163                 break;
2164         case IPV6_RTHDRDSTOPTS:
2165                 if (pktopt && pktopt->ip6po_dest1) {
2166                         optdata = (void *)pktopt->ip6po_dest1;
2167                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2168                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2169                 }
2170                 break;
2171         case IPV6_DSTOPTS:
2172                 if (pktopt && pktopt->ip6po_dest2) {
2173                         optdata = (void *)pktopt->ip6po_dest2;
2174                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2175                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2176                 }
2177                 break;
2178         case IPV6_NEXTHOP:
2179                 if (pktopt && pktopt->ip6po_nexthop) {
2180                         optdata = (void *)pktopt->ip6po_nexthop;
2181                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2182                 }
2183                 break;
2184         case IPV6_USE_MIN_MTU:
2185                 if (pktopt)
2186                         optdata = (void *)&pktopt->ip6po_minmtu;
2187                 else
2188                         optdata = (void *)&defminmtu;
2189                 optdatalen = sizeof(int);
2190                 break;
2191         case IPV6_DONTFRAG:
2192                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2193                         on = 1;
2194                 else
2195                         on = 0;
2196                 optdata = (void *)&on;
2197                 optdatalen = sizeof(on);
2198                 break;
2199         case IPV6_PREFER_TEMPADDR:
2200                 if (pktopt)
2201                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2202                 else
2203                         optdata = (void *)&defpreftemp;
2204                 optdatalen = sizeof(int);
2205                 break;
2206         default:                /* should not happen */
2207 #ifdef DIAGNOSTIC
2208                 panic("ip6_getpcbopt: unexpected option\n");
2209 #endif
2210                 return (ENOPROTOOPT);
2211         }
2212
2213         error = sooptcopyout(sopt, optdata, optdatalen);
2214
2215         return (error);
2216 }
2217
2218 void
2219 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2220 {
2221         if (pktopt == NULL)
2222                 return;
2223
2224         if (optname == -1 || optname == IPV6_PKTINFO) {
2225                 if (pktopt->ip6po_pktinfo)
2226                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2227                 pktopt->ip6po_pktinfo = NULL;
2228         }
2229         if (optname == -1 || optname == IPV6_HOPLIMIT)
2230                 pktopt->ip6po_hlim = -1;
2231         if (optname == -1 || optname == IPV6_TCLASS)
2232                 pktopt->ip6po_tclass = -1;
2233         if (optname == -1 || optname == IPV6_NEXTHOP) {
2234                 if (pktopt->ip6po_nextroute.ro_rt) {
2235                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2236                         pktopt->ip6po_nextroute.ro_rt = NULL;
2237                 }
2238                 if (pktopt->ip6po_nexthop)
2239                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2240                 pktopt->ip6po_nexthop = NULL;
2241         }
2242         if (optname == -1 || optname == IPV6_HOPOPTS) {
2243                 if (pktopt->ip6po_hbh)
2244                         free(pktopt->ip6po_hbh, M_IP6OPT);
2245                 pktopt->ip6po_hbh = NULL;
2246         }
2247         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2248                 if (pktopt->ip6po_dest1)
2249                         free(pktopt->ip6po_dest1, M_IP6OPT);
2250                 pktopt->ip6po_dest1 = NULL;
2251         }
2252         if (optname == -1 || optname == IPV6_RTHDR) {
2253                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2254                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2255                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2256                 if (pktopt->ip6po_route.ro_rt) {
2257                         RTFREE(pktopt->ip6po_route.ro_rt);
2258                         pktopt->ip6po_route.ro_rt = NULL;
2259                 }
2260         }
2261         if (optname == -1 || optname == IPV6_DSTOPTS) {
2262                 if (pktopt->ip6po_dest2)
2263                         free(pktopt->ip6po_dest2, M_IP6OPT);
2264                 pktopt->ip6po_dest2 = NULL;
2265         }
2266 }
2267
2268 #define PKTOPT_EXTHDRCPY(type) \
2269 do {\
2270         if (src->type) {\
2271                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2272                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2273                 if (dst->type == NULL && canwait == M_NOWAIT)\
2274                         goto bad;\
2275                 bcopy(src->type, dst->type, hlen);\
2276         }\
2277 } while (/*CONSTCOND*/ 0)
2278
2279 static int
2280 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2281 {
2282         if (dst == NULL || src == NULL)  {
2283                 printf("ip6_clearpktopts: invalid argument\n");
2284                 return (EINVAL);
2285         }
2286
2287         dst->ip6po_hlim = src->ip6po_hlim;
2288         dst->ip6po_tclass = src->ip6po_tclass;
2289         dst->ip6po_flags = src->ip6po_flags;
2290         if (src->ip6po_pktinfo) {
2291                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2292                     M_IP6OPT, canwait);
2293                 if (dst->ip6po_pktinfo == NULL)
2294                         goto bad;
2295                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2296         }
2297         if (src->ip6po_nexthop) {
2298                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2299                     M_IP6OPT, canwait);
2300                 if (dst->ip6po_nexthop == NULL)
2301                         goto bad;
2302                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2303                     src->ip6po_nexthop->sa_len);
2304         }
2305         PKTOPT_EXTHDRCPY(ip6po_hbh);
2306         PKTOPT_EXTHDRCPY(ip6po_dest1);
2307         PKTOPT_EXTHDRCPY(ip6po_dest2);
2308         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2309         return (0);
2310
2311   bad:
2312         ip6_clearpktopts(dst, -1);
2313         return (ENOBUFS);
2314 }
2315 #undef PKTOPT_EXTHDRCPY
2316
2317 struct ip6_pktopts *
2318 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2319 {
2320         int error;
2321         struct ip6_pktopts *dst;
2322
2323         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2324         if (dst == NULL)
2325                 return (NULL);
2326         ip6_initpktopts(dst);
2327
2328         if ((error = copypktopts(dst, src, canwait)) != 0) {
2329                 free(dst, M_IP6OPT);
2330                 return (NULL);
2331         }
2332
2333         return (dst);
2334 }
2335
2336 void
2337 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2338 {
2339         if (pktopt == NULL)
2340                 return;
2341
2342         ip6_clearpktopts(pktopt, -1);
2343
2344         free(pktopt, M_IP6OPT);
2345 }
2346
2347 /*
2348  * Set IPv6 outgoing packet options based on advanced API.
2349  */
2350 int
2351 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2352     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2353 {
2354         struct cmsghdr *cm = 0;
2355
2356         if (control == NULL || opt == NULL)
2357                 return (EINVAL);
2358
2359         ip6_initpktopts(opt);
2360         if (stickyopt) {
2361                 int error;
2362
2363                 /*
2364                  * If stickyopt is provided, make a local copy of the options
2365                  * for this particular packet, then override them by ancillary
2366                  * objects.
2367                  * XXX: copypktopts() does not copy the cached route to a next
2368                  * hop (if any).  This is not very good in terms of efficiency,
2369                  * but we can allow this since this option should be rarely
2370                  * used.
2371                  */
2372                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2373                         return (error);
2374         }
2375
2376         /*
2377          * XXX: Currently, we assume all the optional information is stored
2378          * in a single mbuf.
2379          */
2380         if (control->m_next)
2381                 return (EINVAL);
2382
2383         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2384             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2385                 int error;
2386
2387                 if (control->m_len < CMSG_LEN(0))
2388                         return (EINVAL);
2389
2390                 cm = mtod(control, struct cmsghdr *);
2391                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2392                         return (EINVAL);
2393                 if (cm->cmsg_level != IPPROTO_IPV6)
2394                         continue;
2395
2396                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2397                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2398                 if (error)
2399                         return (error);
2400         }
2401
2402         return (0);
2403 }
2404
2405 /*
2406  * Set a particular packet option, as a sticky option or an ancillary data
2407  * item.  "len" can be 0 only when it's a sticky option.
2408  * We have 4 cases of combination of "sticky" and "cmsg":
2409  * "sticky=0, cmsg=0": impossible
2410  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2411  * "sticky=1, cmsg=0": RFC3542 socket option
2412  * "sticky=1, cmsg=1": RFC2292 socket option
2413  */
2414 static int
2415 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2416     struct ucred *cred, int sticky, int cmsg, int uproto)
2417 {
2418         int minmtupolicy, preftemp;
2419         int error;
2420
2421         if (!sticky && !cmsg) {
2422 #ifdef DIAGNOSTIC
2423                 printf("ip6_setpktopt: impossible case\n");
2424 #endif
2425                 return (EINVAL);
2426         }
2427
2428         /*
2429          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2430          * not be specified in the context of RFC3542.  Conversely,
2431          * RFC3542 types should not be specified in the context of RFC2292.
2432          */
2433         if (!cmsg) {
2434                 switch (optname) {
2435                 case IPV6_2292PKTINFO:
2436                 case IPV6_2292HOPLIMIT:
2437                 case IPV6_2292NEXTHOP:
2438                 case IPV6_2292HOPOPTS:
2439                 case IPV6_2292DSTOPTS:
2440                 case IPV6_2292RTHDR:
2441                 case IPV6_2292PKTOPTIONS:
2442                         return (ENOPROTOOPT);
2443                 }
2444         }
2445         if (sticky && cmsg) {
2446                 switch (optname) {
2447                 case IPV6_PKTINFO:
2448                 case IPV6_HOPLIMIT:
2449                 case IPV6_NEXTHOP:
2450                 case IPV6_HOPOPTS:
2451                 case IPV6_DSTOPTS:
2452                 case IPV6_RTHDRDSTOPTS:
2453                 case IPV6_RTHDR:
2454                 case IPV6_USE_MIN_MTU:
2455                 case IPV6_DONTFRAG:
2456                 case IPV6_TCLASS:
2457                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2458                         return (ENOPROTOOPT);
2459                 }
2460         }
2461
2462         switch (optname) {
2463         case IPV6_2292PKTINFO:
2464         case IPV6_PKTINFO:
2465         {
2466                 struct ifnet *ifp = NULL;
2467                 struct in6_pktinfo *pktinfo;
2468
2469                 if (len != sizeof(struct in6_pktinfo))
2470                         return (EINVAL);
2471
2472                 pktinfo = (struct in6_pktinfo *)buf;
2473
2474                 /*
2475                  * An application can clear any sticky IPV6_PKTINFO option by
2476                  * doing a "regular" setsockopt with ipi6_addr being
2477                  * in6addr_any and ipi6_ifindex being zero.
2478                  * [RFC 3542, Section 6]
2479                  */
2480                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2481                     pktinfo->ipi6_ifindex == 0 &&
2482                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2483                         ip6_clearpktopts(opt, optname);
2484                         break;
2485                 }
2486
2487                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2488                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2489                         return (EINVAL);
2490                 }
2491
2492                 /* validate the interface index if specified. */
2493                 if (pktinfo->ipi6_ifindex > V_if_index ||
2494                     pktinfo->ipi6_ifindex < 0) {
2495                          return (ENXIO);
2496                 }
2497                 if (pktinfo->ipi6_ifindex) {
2498                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2499                         if (ifp == NULL)
2500                                 return (ENXIO);
2501                 }
2502
2503                 /*
2504                  * We store the address anyway, and let in6_selectsrc()
2505                  * validate the specified address.  This is because ipi6_addr
2506                  * may not have enough information about its scope zone, and
2507                  * we may need additional information (such as outgoing
2508                  * interface or the scope zone of a destination address) to
2509                  * disambiguate the scope.
2510                  * XXX: the delay of the validation may confuse the
2511                  * application when it is used as a sticky option.
2512                  */
2513                 if (opt->ip6po_pktinfo == NULL) {
2514                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2515                             M_IP6OPT, M_NOWAIT);
2516                         if (opt->ip6po_pktinfo == NULL)
2517                                 return (ENOBUFS);
2518                 }
2519                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2520                 break;
2521         }
2522
2523         case IPV6_2292HOPLIMIT:
2524         case IPV6_HOPLIMIT:
2525         {
2526                 int *hlimp;
2527
2528                 /*
2529                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2530                  * to simplify the ordering among hoplimit options.
2531                  */
2532                 if (optname == IPV6_HOPLIMIT && sticky)
2533                         return (ENOPROTOOPT);
2534
2535                 if (len != sizeof(int))
2536                         return (EINVAL);
2537                 hlimp = (int *)buf;
2538                 if (*hlimp < -1 || *hlimp > 255)
2539                         return (EINVAL);
2540
2541                 opt->ip6po_hlim = *hlimp;
2542                 break;
2543         }
2544
2545         case IPV6_TCLASS:
2546         {
2547                 int tclass;
2548
2549                 if (len != sizeof(int))
2550                         return (EINVAL);
2551                 tclass = *(int *)buf;
2552                 if (tclass < -1 || tclass > 255)
2553                         return (EINVAL);
2554
2555                 opt->ip6po_tclass = tclass;
2556                 break;
2557         }
2558
2559         case IPV6_2292NEXTHOP:
2560         case IPV6_NEXTHOP:
2561                 if (cred != NULL) {
2562                         error = priv_check_cred(cred,
2563                             PRIV_NETINET_SETHDROPTS, 0);
2564                         if (error)
2565                                 return (error);
2566                 }
2567
2568                 if (len == 0) { /* just remove the option */
2569                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2570                         break;
2571                 }
2572
2573                 /* check if cmsg_len is large enough for sa_len */
2574                 if (len < sizeof(struct sockaddr) || len < *buf)
2575                         return (EINVAL);
2576
2577                 switch (((struct sockaddr *)buf)->sa_family) {
2578                 case AF_INET6:
2579                 {
2580                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2581                         int error;
2582
2583                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2584                                 return (EINVAL);
2585
2586                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2587                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2588                                 return (EINVAL);
2589                         }
2590                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2591                             != 0) {
2592                                 return (error);
2593                         }
2594                         break;
2595                 }
2596                 case AF_LINK:   /* should eventually be supported */
2597                 default:
2598                         return (EAFNOSUPPORT);
2599                 }
2600
2601                 /* turn off the previous option, then set the new option. */
2602                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2603                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2604                 if (opt->ip6po_nexthop == NULL)
2605                         return (ENOBUFS);
2606                 bcopy(buf, opt->ip6po_nexthop, *buf);
2607                 break;
2608
2609         case IPV6_2292HOPOPTS:
2610         case IPV6_HOPOPTS:
2611         {
2612                 struct ip6_hbh *hbh;
2613                 int hbhlen;
2614
2615                 /*
2616                  * XXX: We don't allow a non-privileged user to set ANY HbH
2617                  * options, since per-option restriction has too much
2618                  * overhead.
2619                  */
2620                 if (cred != NULL) {
2621                         error = priv_check_cred(cred,
2622                             PRIV_NETINET_SETHDROPTS, 0);
2623                         if (error)
2624                                 return (error);
2625                 }
2626
2627                 if (len == 0) {
2628                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2629                         break;  /* just remove the option */
2630                 }
2631
2632                 /* message length validation */
2633                 if (len < sizeof(struct ip6_hbh))
2634                         return (EINVAL);
2635                 hbh = (struct ip6_hbh *)buf;
2636                 hbhlen = (hbh->ip6h_len + 1) << 3;
2637                 if (len != hbhlen)
2638                         return (EINVAL);
2639
2640                 /* turn off the previous option, then set the new option. */
2641                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2642                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2643                 if (opt->ip6po_hbh == NULL)
2644                         return (ENOBUFS);
2645                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2646
2647                 break;
2648         }
2649
2650         case IPV6_2292DSTOPTS:
2651         case IPV6_DSTOPTS:
2652         case IPV6_RTHDRDSTOPTS:
2653         {
2654                 struct ip6_dest *dest, **newdest = NULL;
2655                 int destlen;
2656
2657                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2658                         error = priv_check_cred(cred,
2659                             PRIV_NETINET_SETHDROPTS, 0);
2660                         if (error)
2661                                 return (error);
2662                 }
2663
2664                 if (len == 0) {
2665                         ip6_clearpktopts(opt, optname);
2666                         break;  /* just remove the option */
2667                 }
2668
2669                 /* message length validation */
2670                 if (len < sizeof(struct ip6_dest))
2671                         return (EINVAL);
2672                 dest = (struct ip6_dest *)buf;
2673                 destlen = (dest->ip6d_len + 1) << 3;
2674                 if (len != destlen)
2675                         return (EINVAL);
2676
2677                 /*
2678                  * Determine the position that the destination options header
2679                  * should be inserted; before or after the routing header.
2680                  */
2681                 switch (optname) {
2682                 case IPV6_2292DSTOPTS:
2683                         /*
2684                          * The old advacned API is ambiguous on this point.
2685                          * Our approach is to determine the position based
2686                          * according to the existence of a routing header.
2687                          * Note, however, that this depends on the order of the
2688                          * extension headers in the ancillary data; the 1st
2689                          * part of the destination options header must appear
2690                          * before the routing header in the ancillary data,
2691                          * too.
2692                          * RFC3542 solved the ambiguity by introducing
2693                          * separate ancillary data or option types.
2694                          */
2695                         if (opt->ip6po_rthdr == NULL)
2696                                 newdest = &opt->ip6po_dest1;
2697                         else
2698                                 newdest = &opt->ip6po_dest2;
2699                         break;
2700                 case IPV6_RTHDRDSTOPTS:
2701                         newdest = &opt->ip6po_dest1;
2702                         break;
2703                 case IPV6_DSTOPTS:
2704                         newdest = &opt->ip6po_dest2;
2705                         break;
2706                 }
2707
2708                 /* turn off the previous option, then set the new option. */
2709                 ip6_clearpktopts(opt, optname);
2710                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2711                 if (*newdest == NULL)
2712                         return (ENOBUFS);
2713                 bcopy(dest, *newdest, destlen);
2714
2715                 break;
2716         }
2717
2718         case IPV6_2292RTHDR:
2719         case IPV6_RTHDR:
2720         {
2721                 struct ip6_rthdr *rth;
2722                 int rthlen;
2723
2724                 if (len == 0) {
2725                         ip6_clearpktopts(opt, IPV6_RTHDR);
2726                         break;  /* just remove the option */
2727                 }
2728
2729                 /* message length validation */
2730                 if (len < sizeof(struct ip6_rthdr))
2731                         return (EINVAL);
2732                 rth = (struct ip6_rthdr *)buf;
2733                 rthlen = (rth->ip6r_len + 1) << 3;
2734                 if (len != rthlen)
2735                         return (EINVAL);
2736
2737                 switch (rth->ip6r_type) {
2738                 case IPV6_RTHDR_TYPE_0:
2739                         if (rth->ip6r_len == 0) /* must contain one addr */
2740                                 return (EINVAL);
2741                         if (rth->ip6r_len % 2) /* length must be even */
2742                                 return (EINVAL);
2743                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2744                                 return (EINVAL);
2745                         break;
2746                 default:
2747                         return (EINVAL);        /* not supported */
2748                 }
2749
2750                 /* turn off the previous option */
2751                 ip6_clearpktopts(opt, IPV6_RTHDR);
2752                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2753                 if (opt->ip6po_rthdr == NULL)
2754                         return (ENOBUFS);
2755                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2756
2757                 break;
2758         }
2759
2760         case IPV6_USE_MIN_MTU:
2761                 if (len != sizeof(int))
2762                         return (EINVAL);
2763                 minmtupolicy = *(int *)buf;
2764                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2765                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2766                     minmtupolicy != IP6PO_MINMTU_ALL) {
2767                         return (EINVAL);
2768                 }
2769                 opt->ip6po_minmtu = minmtupolicy;
2770                 break;
2771
2772         case IPV6_DONTFRAG:
2773                 if (len != sizeof(int))
2774                         return (EINVAL);
2775
2776                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2777                         /*
2778                          * we ignore this option for TCP sockets.
2779                          * (RFC3542 leaves this case unspecified.)
2780                          */
2781                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2782                 } else
2783                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2784                 break;
2785
2786         case IPV6_PREFER_TEMPADDR:
2787                 if (len != sizeof(int))
2788                         return (EINVAL);
2789                 preftemp = *(int *)buf;
2790                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2791                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2792                     preftemp != IP6PO_TEMPADDR_PREFER) {
2793                         return (EINVAL);
2794                 }
2795                 opt->ip6po_prefer_tempaddr = preftemp;
2796                 break;
2797
2798         default:
2799                 return (ENOPROTOOPT);
2800         } /* end of switch */
2801
2802         return (0);
2803 }
2804
2805 /*
2806  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2807  * packet to the input queue of a specified interface.  Note that this
2808  * calls the output routine of the loopback "driver", but with an interface
2809  * pointer that might NOT be &loif -- easier than replicating that code here.
2810  */
2811 void
2812 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2813 {
2814         struct mbuf *copym;
2815         struct ip6_hdr *ip6;
2816
2817         copym = m_copy(m, 0, M_COPYALL);
2818         if (copym == NULL)
2819                 return;
2820
2821         /*
2822          * Make sure to deep-copy IPv6 header portion in case the data
2823          * is in an mbuf cluster, so that we can safely override the IPv6
2824          * header portion later.
2825          */
2826         if ((copym->m_flags & M_EXT) != 0 ||
2827             copym->m_len < sizeof(struct ip6_hdr)) {
2828                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
2829                 if (copym == NULL)
2830                         return;
2831         }
2832
2833 #ifdef DIAGNOSTIC
2834         if (copym->m_len < sizeof(*ip6)) {
2835                 m_freem(copym);
2836                 return;
2837         }
2838 #endif
2839
2840         ip6 = mtod(copym, struct ip6_hdr *);
2841         /*
2842          * clear embedded scope identifiers if necessary.
2843          * in6_clearscope will touch the addresses only when necessary.
2844          */
2845         in6_clearscope(&ip6->ip6_src);
2846         in6_clearscope(&ip6->ip6_dst);
2847
2848         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
2849 }
2850
2851 /*
2852  * Chop IPv6 header off from the payload.
2853  */
2854 static int
2855 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
2856 {
2857         struct mbuf *mh;
2858         struct ip6_hdr *ip6;
2859
2860         ip6 = mtod(m, struct ip6_hdr *);
2861         if (m->m_len > sizeof(*ip6)) {
2862                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
2863                 if (mh == 0) {
2864                         m_freem(m);
2865                         return ENOBUFS;
2866                 }
2867                 M_MOVE_PKTHDR(mh, m);
2868                 MH_ALIGN(mh, sizeof(*ip6));
2869                 m->m_len -= sizeof(*ip6);
2870                 m->m_data += sizeof(*ip6);
2871                 mh->m_next = m;
2872                 m = mh;
2873                 m->m_len = sizeof(*ip6);
2874                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
2875         }
2876         exthdrs->ip6e_ip6 = m;
2877         return 0;
2878 }
2879
2880 /*
2881  * Compute IPv6 extension header length.
2882  */
2883 int
2884 ip6_optlen(struct inpcb *in6p)
2885 {
2886         int len;
2887
2888         if (!in6p->in6p_outputopts)
2889                 return 0;
2890
2891         len = 0;
2892 #define elen(x) \
2893     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
2894
2895         len += elen(in6p->in6p_outputopts->ip6po_hbh);
2896         if (in6p->in6p_outputopts->ip6po_rthdr)
2897                 /* dest1 is valid with rthdr only */
2898                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
2899         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
2900         len += elen(in6p->in6p_outputopts->ip6po_dest2);
2901         return len;
2902 #undef elen
2903 }