sys/netinet6/ip6_output.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipfw.h"
  69 #include "opt_ipsec.h"
  70 #include "opt_sctp.h"
  71 #include "opt_route.h"
  72
  73 #include <sys/param.h>
  74 #include <sys/kernel.h>
  75 #include <sys/malloc.h>
  76 #include <sys/mbuf.h>
  77 #include <sys/errno.h>
  78 #include <sys/priv.h>
  79 #include <sys/proc.h>
  80 #include <sys/protosw.h>
  81 #include <sys/socket.h>
  82 #include <sys/socketvar.h>
  83 #include <sys/syslog.h>
  84 #include <sys/ucred.h>
  85
  86 #include <machine/in_cksum.h>
  87
  88 #include <net/if.h>
  89 #include <net/netisr.h>
  90 #include <net/route.h>
  91 #include <net/pfil.h>
  92 #include <net/vnet.h>
  93
  94 #include <netinet/in.h>
  95 #include <netinet/in_var.h>
  96 #include <netinet/ip_var.h>
  97 #include <netinet6/in6_var.h>
  98 #include <netinet/ip6.h>
  99 #include <netinet/icmp6.h>
 100 #include <netinet6/ip6_var.h>
 101 #include <netinet/in_pcb.h>
 102 #include <netinet/tcp_var.h>
 103 #include <netinet6/nd6.h>
 104
 105 #ifdef IPSEC
 106 #include <netipsec/ipsec.h>
 107 #include <netipsec/ipsec6.h>
 108 #include <netipsec/key.h>
 109 #include <netinet6/ip6_ipsec.h>
 110 #endif /* IPSEC */
 111 #ifdef SCTP
 112 #include <netinet/sctp.h>
 113 #include <netinet/sctp_crc32.h>
 114 #endif
 115
 116 #include <netinet6/ip6protosw.h>
 117 #include <netinet6/scope6_var.h>
 118
 119 #ifdef FLOWTABLE
 120 #include <net/flowtable.h>
 121 #endif
 122
 123 extern int in6_mcast_loop;
 124
 125 struct ip6_exthdrs {
 126         struct mbuf *ip6e_ip6;
 127         struct mbuf *ip6e_hbh;
 128         struct mbuf *ip6e_dest1;
 129         struct mbuf *ip6e_rthdr;
 130         struct mbuf *ip6e_dest2;
 131 };
 132
 133 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
 134                            struct ucred *, int);
 135 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
 136         struct socket *, struct sockopt *);
 137 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
 138 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
 139         struct ucred *, int, int, int);
 140
 141 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 142 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
 143         struct ip6_frag **);
 144 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 145 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 146 static int ip6_getpmtu(struct route_in6 *, struct route_in6 *,
 147         struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
 148 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 149
 150
 151 /*
 152  * Make an extension header from option data.  hp is the source, and
 153  * mp is the destination.
 154  */
 155 #define MAKE_EXTHDR(hp, mp)                                             \
 156     do {                                                                \
 157         if (hp) {                                                       \
 158                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 159                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 160                     ((eh)->ip6e_len + 1) << 3);                         \
 161                 if (error)                                              \
 162                         goto freehdrs;                                  \
 163         }                                                               \
 164     } while (/*CONSTCOND*/ 0)
 165
 166 /*
 167  * Form a chain of extension headers.
 168  * m is the extension header mbuf
 169  * mp is the previous mbuf in the chain
 170  * p is the next header
 171  * i is the type of option.
 172  */
 173 #define MAKE_CHAIN(m, mp, p, i)\
 174     do {\
 175         if (m) {\
 176                 if (!hdrsplit) \
 177                         panic("assumption failed: hdr not split"); \
 178                 *mtod((m), u_char *) = *(p);\
 179                 *(p) = (i);\
 180                 p = mtod((m), u_char *);\
 181                 (m)->m_next = (mp)->m_next;\
 182                 (mp)->m_next = (m);\
 183                 (mp) = (m);\
 184         }\
 185     } while (/*CONSTCOND*/ 0)
 186
 187 void
 188 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
 189 {
 190         u_short csum;
 191
 192         csum = in_cksum_skip(m, offset + plen, offset);
 193         if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
 194                 csum = 0xffff;
 195         offset += m->m_pkthdr.csum_data;        /* checksum offset */
 196
 197         if (offset + sizeof(u_short) > m->m_len) {
 198                 printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
 199                     "csum_flags=0x%04x\n", __func__, m->m_len, plen, offset,
 200                     m->m_pkthdr.csum_flags);
 201                 /*
 202                  * XXX this should not happen, but if it does, the correct
 203                  * behavior may be to insert the checksum in the appropriate
 204                  * next mbuf in the chain.
 205                  */
 206                 return;
 207         }
 208         *(u_short *)(m->m_data + offset) = csum;
 209 }
 210
 211 /*
 212  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 213  * header (with pri, len, nxt, hlim, src, dst).
 214  * This function may modify ver and hlim only.
 215  * The mbuf chain containing the packet will be freed.
 216  * The mbuf opt, if present, will not be freed.
 217  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
 218  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
 219  * then result of route lookup is stored in ro->ro_rt.
 220  *
 221  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
 222  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 223  * which is rt_rmx.rmx_mtu.
 224  *
 225  * ifpp - XXX: just for statistics
 226  */
 227 int
 228 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 229     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 230     struct ifnet **ifpp, struct inpcb *inp)
 231 {
 232         struct ip6_hdr *ip6, *mhip6;
 233         struct ifnet *ifp, *origifp;
 234         struct mbuf *m = m0;
 235         struct mbuf *mprev = NULL;
 236         int hlen, tlen, len, off;
 237         struct route_in6 ip6route;
 238         struct rtentry *rt = NULL;
 239         struct sockaddr_in6 *dst, src_sa, dst_sa;
 240         struct in6_addr odst;
 241         int error = 0;
 242         struct in6_ifaddr *ia = NULL;
 243         u_long mtu;
 244         int alwaysfrag, dontfrag;
 245         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 246         struct ip6_exthdrs exthdrs;
 247         struct in6_addr finaldst, src0, dst0;
 248         u_int32_t zone;
 249         struct route_in6 *ro_pmtu = NULL;
 250         int hdrsplit = 0;
 251         int needipsec = 0;
 252         int sw_csum, tso;
 253 #ifdef IPSEC
 254         struct ipsec_output_state state;
 255         struct ip6_rthdr *rh = NULL;
 256         int needipsectun = 0;
 257         int segleft_org = 0;
 258         struct secpolicy *sp = NULL;
 259 #endif /* IPSEC */
 260         struct m_tag *fwd_tag = NULL;
 261
 262         ip6 = mtod(m, struct ip6_hdr *);
 263         if (ip6 == NULL) {
 264                 printf ("ip6 is NULL");
 265                 goto bad;
 266         }
 267
 268         if (inp != NULL)
 269                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
 270
 271         finaldst = ip6->ip6_dst;
 272         bzero(&exthdrs, sizeof(exthdrs));
 273         if (opt) {
 274                 /* Hop-by-Hop options header */
 275                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 276                 /* Destination options header(1st part) */
 277                 if (opt->ip6po_rthdr) {
 278                         /*
 279                          * Destination options header(1st part)
 280                          * This only makes sense with a routing header.
 281                          * See Section 9.2 of RFC 3542.
 282                          * Disabling this part just for MIP6 convenience is
 283                          * a bad idea.  We need to think carefully about a
 284                          * way to make the advanced API coexist with MIP6
 285                          * options, which might automatically be inserted in
 286                          * the kernel.
 287                          */
 288                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 289                 }
 290                 /* Routing header */
 291                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 292                 /* Destination options header(2nd part) */
 293                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 294         }
 295
 296 #ifdef IPSEC
 297         /*
 298          * IPSec checking which handles several cases.
 299          * FAST IPSEC: We re-injected the packet.
 300          */
 301         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
 302         {
 303         case 1:                 /* Bad packet */
 304                 goto freehdrs;
 305         case -1:                /* Do IPSec */
 306                 needipsec = 1;
 307                 /*
 308                  * Do delayed checksums now, as we may send before returning.
 309                  */
 310                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 311                         plen = m->m_pkthdr.len - sizeof(*ip6);
 312                         in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
 313                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
 314                 }
 315 #ifdef SCTP
 316                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
 317                         sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 318                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
 319                 }
 320 #endif
 321         case 0:                 /* No IPSec */
 322         default:
 323                 break;
 324         }
 325 #endif /* IPSEC */
 326
 327         /*
 328          * Calculate the total length of the extension header chain.
 329          * Keep the length of the unfragmentable part for fragmentation.
 330          */
 331         optlen = 0;
 332         if (exthdrs.ip6e_hbh)
 333                 optlen += exthdrs.ip6e_hbh->m_len;
 334         if (exthdrs.ip6e_dest1)
 335                 optlen += exthdrs.ip6e_dest1->m_len;
 336         if (exthdrs.ip6e_rthdr)
 337                 optlen += exthdrs.ip6e_rthdr->m_len;
 338         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 339
 340         /* NOTE: we don't add AH/ESP length here. do that later. */
 341         if (exthdrs.ip6e_dest2)
 342                 optlen += exthdrs.ip6e_dest2->m_len;
 343
 344         /*
 345          * If we need IPsec, or there is at least one extension header,
 346          * separate IP6 header from the payload.
 347          */
 348         if ((needipsec || optlen) && !hdrsplit) {
 349                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 350                         m = NULL;
 351                         goto freehdrs;
 352                 }
 353                 m = exthdrs.ip6e_ip6;
 354                 hdrsplit++;
 355         }
 356
 357         /* adjust pointer */
 358         ip6 = mtod(m, struct ip6_hdr *);
 359
 360         /* adjust mbuf packet header length */
 361         m->m_pkthdr.len += optlen;
 362         plen = m->m_pkthdr.len - sizeof(*ip6);
 363
 364         /* If this is a jumbo payload, insert a jumbo payload option. */
 365         if (plen > IPV6_MAXPACKET) {
 366                 if (!hdrsplit) {
 367                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 368                                 m = NULL;
 369                                 goto freehdrs;
 370                         }
 371                         m = exthdrs.ip6e_ip6;
 372                         hdrsplit++;
 373                 }
 374                 /* adjust pointer */
 375                 ip6 = mtod(m, struct ip6_hdr *);
 376                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 377                         goto freehdrs;
 378                 ip6->ip6_plen = 0;
 379         } else
 380                 ip6->ip6_plen = htons(plen);
 381
 382         /*
 383          * Concatenate headers and fill in next header fields.
 384          * Here we have, on "m"
 385          *      IPv6 payload
 386          * and we insert headers accordingly.  Finally, we should be getting:
 387          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 388          *
 389          * during the header composing process, "m" points to IPv6 header.
 390          * "mprev" points to an extension header prior to esp.
 391          */
 392         u_char *nexthdrp = &ip6->ip6_nxt;
 393         mprev = m;
 394
 395         /*
 396          * we treat dest2 specially.  this makes IPsec processing
 397          * much easier.  the goal here is to make mprev point the
 398          * mbuf prior to dest2.
 399          *
 400          * result: IPv6 dest2 payload
 401          * m and mprev will point to IPv6 header.
 402          */
 403         if (exthdrs.ip6e_dest2) {
 404                 if (!hdrsplit)
 405                         panic("assumption failed: hdr not split");
 406                 exthdrs.ip6e_dest2->m_next = m->m_next;
 407                 m->m_next = exthdrs.ip6e_dest2;
 408                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 409                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 410         }
 411
 412         /*
 413          * result: IPv6 hbh dest1 rthdr dest2 payload
 414          * m will point to IPv6 header.  mprev will point to the
 415          * extension header prior to dest2 (rthdr in the above case).
 416          */
 417         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 418         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 419                    IPPROTO_DSTOPTS);
 420         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 421                    IPPROTO_ROUTING);
 422
 423 #ifdef IPSEC
 424         if (!needipsec)
 425                 goto skip_ipsec2;
 426
 427         /*
 428          * pointers after IPsec headers are not valid any more.
 429          * other pointers need a great care too.
 430          * (IPsec routines should not mangle mbufs prior to AH/ESP)
 431          */
 432         exthdrs.ip6e_dest2 = NULL;
 433
 434         if (exthdrs.ip6e_rthdr) {
 435                 rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
 436                 segleft_org = rh->ip6r_segleft;
 437                 rh->ip6r_segleft = 0;
 438         }
 439
 440         bzero(&state, sizeof(state));
 441         state.m = m;
 442         error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
 443                                     &needipsectun);
 444         m = state.m;
 445         if (error == EJUSTRETURN) {
 446                 /*
 447                  * We had a SP with a level of 'use' and no SA. We
 448                  * will just continue to process the packet without
 449                  * IPsec processing.
 450                  */
 451                 ;
 452         } else if (error) {
 453                 /* mbuf is already reclaimed in ipsec6_output_trans. */
 454                 m = NULL;
 455                 switch (error) {
 456                 case EHOSTUNREACH:
 457                 case ENETUNREACH:
 458                 case EMSGSIZE:
 459                 case ENOBUFS:
 460                 case ENOMEM:
 461                         break;
 462                 default:
 463                         printf("[%s:%d] (ipsec): error code %d\n",
 464                             __func__, __LINE__, error);
 465                         /* FALLTHROUGH */
 466                 case ENOENT:
 467                         /* don't show these error codes to the user */
 468                         error = 0;
 469                         break;
 470                 }
 471                 goto bad;
 472         } else if (!needipsectun) {
 473                 /*
 474                  * In the FAST IPSec case we have already
 475                  * re-injected the packet and it has been freed
 476                  * by the ipsec_done() function.  So, just clean
 477                  * up after ourselves.
 478                  */
 479                 m = NULL;
 480                 goto done;
 481         }
 482         if (exthdrs.ip6e_rthdr) {
 483                 /* ah6_output doesn't modify mbuf chain */
 484                 rh->ip6r_segleft = segleft_org;
 485         }
 486 skip_ipsec2:;
 487 #endif /* IPSEC */
 488
 489         /*
 490          * If there is a routing header, discard the packet.
 491          */
 492         if (exthdrs.ip6e_rthdr) {
 493                  error = EINVAL;
 494                  goto bad;
 495         }
 496
 497         /* Source address validation */
 498         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 499             (flags & IPV6_UNSPECSRC) == 0) {
 500                 error = EOPNOTSUPP;
 501                 IP6STAT_INC(ip6s_badscope);
 502                 goto bad;
 503         }
 504         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 505                 error = EOPNOTSUPP;
 506                 IP6STAT_INC(ip6s_badscope);
 507                 goto bad;
 508         }
 509
 510         IP6STAT_INC(ip6s_localout);
 511
 512         /*
 513          * Route packet.
 514          */
 515         if (ro == 0) {
 516                 ro = &ip6route;
 517                 bzero((caddr_t)ro, sizeof(*ro));
 518         }
 519         ro_pmtu = ro;
 520         if (opt && opt->ip6po_rthdr)
 521                 ro = &opt->ip6po_route;
 522         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 523 #ifdef FLOWTABLE
 524         if (ro->ro_rt == NULL) {
 525                 struct flentry *fle;
 526
 527                 /*
 528                  * The flow table returns route entries valid for up to 30
 529                  * seconds; we rely on the remainder of ip_output() taking no
 530                  * longer than that long for the stability of ro_rt.  The
 531                  * flow ID assignment must have happened before this point.
 532                  */
 533                 fle = flowtable_lookup_mbuf(V_ip6_ft, m, AF_INET6);
 534                 if (fle != NULL)
 535                         flow_to_route_in6(fle, ro);
 536         }
 537 #endif
 538 again:
 539         /*
 540          * if specified, try to fill in the traffic class field.
 541          * do not override if a non-zero value is already set.
 542          * we check the diffserv field and the ecn field separately.
 543          */
 544         if (opt && opt->ip6po_tclass >= 0) {
 545                 int mask = 0;
 546
 547                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 548                         mask |= 0xfc;
 549                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 550                         mask |= 0x03;
 551                 if (mask != 0)
 552                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 553         }
 554
 555         /* fill in or override the hop limit field, if necessary. */
 556         if (opt && opt->ip6po_hlim != -1)
 557                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 558         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 559                 if (im6o != NULL)
 560                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 561                 else
 562                         ip6->ip6_hlim = V_ip6_defmcasthlim;
 563         }
 564
 565 #ifdef IPSEC
 566         /*
 567          * We may re-inject packets into the stack here.
 568          */
 569         if (needipsec && needipsectun) {
 570                 struct ipsec_output_state state;
 571
 572                 /*
 573                  * All the extension headers will become inaccessible
 574                  * (since they can be encrypted).
 575                  * Don't panic, we need no more updates to extension headers
 576                  * on inner IPv6 packet (since they are now encapsulated).
 577                  *
 578                  * IPv6 [ESP|AH] IPv6 [extension headers] payload
 579                  */
 580                 bzero(&exthdrs, sizeof(exthdrs));
 581                 exthdrs.ip6e_ip6 = m;
 582
 583                 bzero(&state, sizeof(state));
 584                 state.m = m;
 585                 state.ro = (struct route *)ro;
 586                 state.dst = (struct sockaddr *)dst;
 587
 588                 error = ipsec6_output_tunnel(&state, sp, flags);
 589
 590                 m = state.m;
 591                 ro = (struct route_in6 *)state.ro;
 592                 dst = (struct sockaddr_in6 *)state.dst;
 593                 if (error == EJUSTRETURN) {
 594                         /*
 595                          * We had a SP with a level of 'use' and no SA. We
 596                          * will just continue to process the packet without
 597                          * IPsec processing.
 598                          */
 599                         ;
 600                 } else if (error) {
 601                         /* mbuf is already reclaimed in ipsec6_output_tunnel. */
 602                         m0 = m = NULL;
 603                         m = NULL;
 604                         switch (error) {
 605                         case EHOSTUNREACH:
 606                         case ENETUNREACH:
 607                         case EMSGSIZE:
 608                         case ENOBUFS:
 609                         case ENOMEM:
 610                                 break;
 611                         default:
 612                                 printf("[%s:%d] (ipsec): error code %d\n",
 613                                     __func__, __LINE__, error);
 614                                 /* FALLTHROUGH */
 615                         case ENOENT:
 616                                 /* don't show these error codes to the user */
 617                                 error = 0;
 618                                 break;
 619                         }
 620                         goto bad;
 621                 } else {
 622                         /*
 623                          * In the FAST IPSec case we have already
 624                          * re-injected the packet and it has been freed
 625                          * by the ipsec_done() function.  So, just clean
 626                          * up after ourselves.
 627                          */
 628                         m = NULL;
 629                         goto done;
 630                 }
 631
 632                 exthdrs.ip6e_ip6 = m;
 633         }
 634 #endif /* IPSEC */
 635
 636         /* adjust pointer */
 637         ip6 = mtod(m, struct ip6_hdr *);
 638
 639         if (ro->ro_rt && fwd_tag == NULL) {
 640                 rt = ro->ro_rt;
 641                 ifp = ro->ro_rt->rt_ifp;
 642         } else {
 643                 if (fwd_tag == NULL) {
 644                         bzero(&dst_sa, sizeof(dst_sa));
 645                         dst_sa.sin6_family = AF_INET6;
 646                         dst_sa.sin6_len = sizeof(dst_sa);
 647                         dst_sa.sin6_addr = ip6->ip6_dst;
 648                 }
 649                 error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
 650                     &rt, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
 651                 if (error != 0) {
 652                         if (ifp != NULL)
 653                                 in6_ifstat_inc(ifp, ifs6_out_discard);
 654                         goto bad;
 655                 }
 656         }
 657         if (rt == NULL) {
 658                 /*
 659                  * If in6_selectroute() does not return a route entry,
 660                  * dst may not have been updated.
 661                  */
 662                 *dst = dst_sa;  /* XXX */
 663         }
 664
 665         /*
 666          * then rt (for unicast) and ifp must be non-NULL valid values.
 667          */
 668         if ((flags & IPV6_FORWARDING) == 0) {
 669                 /* XXX: the FORWARDING flag can be set for mrouting. */
 670                 in6_ifstat_inc(ifp, ifs6_out_request);
 671         }
 672         if (rt != NULL) {
 673                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 674                 rt->rt_use++;
 675         }
 676
 677
 678         /*
 679          * The outgoing interface must be in the zone of source and
 680          * destination addresses.
 681          */
 682         origifp = ifp;
 683
 684         src0 = ip6->ip6_src;
 685         if (in6_setscope(&src0, origifp, &zone))
 686                 goto badscope;
 687         bzero(&src_sa, sizeof(src_sa));
 688         src_sa.sin6_family = AF_INET6;
 689         src_sa.sin6_len = sizeof(src_sa);
 690         src_sa.sin6_addr = ip6->ip6_src;
 691         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 692                 goto badscope;
 693
 694         dst0 = ip6->ip6_dst;
 695         if (in6_setscope(&dst0, origifp, &zone))
 696                 goto badscope;
 697         /* re-initialize to be sure */
 698         bzero(&dst_sa, sizeof(dst_sa));
 699         dst_sa.sin6_family = AF_INET6;
 700         dst_sa.sin6_len = sizeof(dst_sa);
 701         dst_sa.sin6_addr = ip6->ip6_dst;
 702         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 703                 goto badscope;
 704         }
 705
 706         /* We should use ia_ifp to support the case of
 707          * sending packets to an address of our own.
 708          */
 709         if (ia != NULL && ia->ia_ifp)
 710                 ifp = ia->ia_ifp;
 711
 712         /* scope check is done. */
 713         goto routefound;
 714
 715   badscope:
 716         IP6STAT_INC(ip6s_badscope);
 717         in6_ifstat_inc(origifp, ifs6_out_discard);
 718         if (error == 0)
 719                 error = EHOSTUNREACH; /* XXX */
 720         goto bad;
 721
 722   routefound:
 723         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 724                 if (opt && opt->ip6po_nextroute.ro_rt) {
 725                         /*
 726                          * The nexthop is explicitly specified by the
 727                          * application.  We assume the next hop is an IPv6
 728                          * address.
 729                          */
 730                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 731                 }
 732                 else if ((rt->rt_flags & RTF_GATEWAY))
 733                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 734         }
 735
 736         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 737                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 738         } else {
 739                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 740                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 741                 /*
 742                  * Confirm that the outgoing interface supports multicast.
 743                  */
 744                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 745                         IP6STAT_INC(ip6s_noroute);
 746                         in6_ifstat_inc(ifp, ifs6_out_discard);
 747                         error = ENETUNREACH;
 748                         goto bad;
 749                 }
 750                 if ((im6o == NULL && in6_mcast_loop) ||
 751                     (im6o && im6o->im6o_multicast_loop)) {
 752                         /*
 753                          * Loop back multicast datagram if not expressly
 754                          * forbidden to do so, even if we have not joined
 755                          * the address; protocols will filter it later,
 756                          * thus deferring a hash lookup and lock acquisition
 757                          * at the expense of an m_copym().
 758                          */
 759                         ip6_mloopback(ifp, m, dst);
 760                 } else {
 761                         /*
 762                          * If we are acting as a multicast router, perform
 763                          * multicast forwarding as if the packet had just
 764                          * arrived on the interface to which we are about
 765                          * to send.  The multicast forwarding function
 766                          * recursively calls this function, using the
 767                          * IPV6_FORWARDING flag to prevent infinite recursion.
 768                          *
 769                          * Multicasts that are looped back by ip6_mloopback(),
 770                          * above, will be forwarded by the ip6_input() routine,
 771                          * if necessary.
 772                          */
 773                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 774                                 /*
 775                                  * XXX: ip6_mforward expects that rcvif is NULL
 776                                  * when it is called from the originating path.
 777                                  * However, it is not always the case, since
 778                                  * some versions of MGETHDR() does not
 779                                  * initialize the field.
 780                                  */
 781                                 m->m_pkthdr.rcvif = NULL;
 782                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 783                                         m_freem(m);
 784                                         goto done;
 785                                 }
 786                         }
 787                 }
 788                 /*
 789                  * Multicasts with a hoplimit of zero may be looped back,
 790                  * above, but must not be transmitted on a network.
 791                  * Also, multicasts addressed to the loopback interface
 792                  * are not sent -- the above call to ip6_mloopback() will
 793                  * loop back a copy if this host actually belongs to the
 794                  * destination group on the loopback interface.
 795                  */
 796                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 797                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 798                         m_freem(m);
 799                         goto done;
 800                 }
 801         }
 802
 803         /*
 804          * Fill the outgoing inteface to tell the upper layer
 805          * to increment per-interface statistics.
 806          */
 807         if (ifpp)
 808                 *ifpp = ifp;
 809
 810         /* Determine path MTU. */
 811         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
 812             &alwaysfrag, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m))) != 0)
 813                 goto bad;
 814
 815         /*
 816          * The caller of this function may specify to use the minimum MTU
 817          * in some cases.
 818          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 819          * setting.  The logic is a bit complicated; by default, unicast
 820          * packets will follow path MTU while multicast packets will be sent at
 821          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 822          * including unicast ones will be sent at the minimum MTU.  Multicast
 823          * packets will always be sent at the minimum MTU unless
 824          * IP6PO_MINMTU_DISABLE is explicitly specified.
 825          * See RFC 3542 for more details.
 826          */
 827         if (mtu > IPV6_MMTU) {
 828                 if ((flags & IPV6_MINMTU))
 829                         mtu = IPV6_MMTU;
 830                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 831                         mtu = IPV6_MMTU;
 832                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 833                          (opt == NULL ||
 834                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 835                         mtu = IPV6_MMTU;
 836                 }
 837         }
 838
 839         /*
 840          * clear embedded scope identifiers if necessary.
 841          * in6_clearscope will touch the addresses only when necessary.
 842          */
 843         in6_clearscope(&ip6->ip6_src);
 844         in6_clearscope(&ip6->ip6_dst);
 845
 846         /*
 847          * If the outgoing packet contains a hop-by-hop options header,
 848          * it must be examined and processed even by the source node.
 849          * (RFC 2460, section 4.)
 850          */
 851         if (exthdrs.ip6e_hbh) {
 852                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 853                 u_int32_t dummy; /* XXX unused */
 854                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 855
 856 #ifdef DIAGNOSTIC
 857                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 858                         panic("ip6e_hbh is not contiguous");
 859 #endif
 860                 /*
 861                  *  XXX: if we have to send an ICMPv6 error to the sender,
 862                  *       we need the M_LOOP flag since icmp6_error() expects
 863                  *       the IPv6 and the hop-by-hop options header are
 864                  *       contiguous unless the flag is set.
 865                  */
 866                 m->m_flags |= M_LOOP;
 867                 m->m_pkthdr.rcvif = ifp;
 868                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 869                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 870                     &dummy, &plen) < 0) {
 871                         /* m was already freed at this point */
 872                         error = EINVAL;/* better error? */
 873                         goto done;
 874                 }
 875                 m->m_flags &= ~M_LOOP; /* XXX */
 876                 m->m_pkthdr.rcvif = NULL;
 877         }
 878
 879         /* Jump over all PFIL processing if hooks are not active. */
 880         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
 881                 goto passout;
 882
 883         odst = ip6->ip6_dst;
 884         /* Run through list of hooks for output packets. */
 885         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 886         if (error != 0 || m == NULL)
 887                 goto done;
 888         ip6 = mtod(m, struct ip6_hdr *);
 889
 890         /* See if destination IP address was changed by packet filter. */
 891         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 892                 m->m_flags |= M_SKIP_FIREWALL;
 893                 /* If destination is now ourself drop to ip6_input(). */
 894                 if (in6_localip(&ip6->ip6_dst)) {
 895                         m->m_flags |= M_FASTFWD_OURS;
 896                         if (m->m_pkthdr.rcvif == NULL)
 897                                 m->m_pkthdr.rcvif = V_loif;
 898                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 899                                 m->m_pkthdr.csum_flags |=
 900                                     CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 901                                 m->m_pkthdr.csum_data = 0xffff;
 902                         }
 903 #ifdef SCTP
 904                         if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 905                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 906 #endif
 907                         error = netisr_queue(NETISR_IPV6, m);
 908                         goto done;
 909                 } else
 910                         goto again;     /* Redo the routing table lookup. */
 911         }
 912
 913         /* See if local, if yes, send it to netisr. */
 914         if (m->m_flags & M_FASTFWD_OURS) {
 915                 if (m->m_pkthdr.rcvif == NULL)
 916                         m->m_pkthdr.rcvif = V_loif;
 917                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 918                         m->m_pkthdr.csum_flags |=
 919                             CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 920                         m->m_pkthdr.csum_data = 0xffff;
 921                 }
 922 #ifdef SCTP
 923                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 924                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 925 #endif
 926                 error = netisr_queue(NETISR_IPV6, m);
 927                 goto done;
 928         }
 929         /* Or forward to some other address? */
 930         if ((m->m_flags & M_IP6_NEXTHOP) &&
 931             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 932                 dst = (struct sockaddr_in6 *)&ro->ro_dst;
 933                 bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
 934                 m->m_flags |= M_SKIP_FIREWALL;
 935                 m->m_flags &= ~M_IP6_NEXTHOP;
 936                 m_tag_delete(m, fwd_tag);
 937                 goto again;
 938         }
 939
 940 passout:
 941         /*
 942          * Send the packet to the outgoing interface.
 943          * If necessary, do IPv6 fragmentation before sending.
 944          *
 945          * the logic here is rather complex:
 946          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 947          * 1-a: send as is if tlen <= path mtu
 948          * 1-b: fragment if tlen > path mtu
 949          *
 950          * 2: if user asks us not to fragment (dontfrag == 1)
 951          * 2-a: send as is if tlen <= interface mtu
 952          * 2-b: error if tlen > interface mtu
 953          *
 954          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 955          *      always fragment
 956          *
 957          * 4: if dontfrag == 1 && alwaysfrag == 1
 958          *      error, as we cannot handle this conflicting request
 959          */
 960         sw_csum = m->m_pkthdr.csum_flags;
 961         if (!hdrsplit) {
 962                 tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
 963                 sw_csum &= ~ifp->if_hwassist;
 964         } else
 965                 tso = 0;
 966         /*
 967          * If we added extension headers, we will not do TSO and calculate the
 968          * checksums ourselves for now.
 969          * XXX-BZ  Need a framework to know when the NIC can handle it, even
 970          * with ext. hdrs.
 971          */
 972         if (sw_csum & CSUM_DELAY_DATA_IPV6) {
 973                 sw_csum &= ~CSUM_DELAY_DATA_IPV6;
 974                 in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
 975         }
 976 #ifdef SCTP
 977         if (sw_csum & CSUM_SCTP_IPV6) {
 978                 sw_csum &= ~CSUM_SCTP_IPV6;
 979                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 980         }
 981 #endif
 982         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
 983         tlen = m->m_pkthdr.len;
 984
 985         if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
 986                 dontfrag = 1;
 987         else
 988                 dontfrag = 0;
 989         if (dontfrag && alwaysfrag) {   /* case 4 */
 990                 /* conflicting request - can't transmit */
 991                 error = EMSGSIZE;
 992                 goto bad;
 993         }
 994         if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {      /* case 2-b */
 995                 /*
 996                  * Even if the DONTFRAG option is specified, we cannot send the
 997                  * packet when the data length is larger than the MTU of the
 998                  * outgoing interface.
 999                  * Notify the error by sending IPV6_PATHMTU ancillary data if
1000                  * application wanted to know the MTU value. Also return an
1001                  * error code (this is not described in the API spec).
1002                  */
1003                 if (inp != NULL)
1004                         ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
1005                 error = EMSGSIZE;
1006                 goto bad;
1007         }
1008
1009         /*
1010          * transmit packet without fragmentation
1011          */
1012         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
1013                 struct in6_ifaddr *ia6;
1014
1015                 ip6 = mtod(m, struct ip6_hdr *);
1016                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
1017                 if (ia6) {
1018                         /* Record statistics for this interface address. */
1019                         ia6->ia_ifa.if_opackets++;
1020                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
1021                         ifa_free(&ia6->ia_ifa);
1022                 }
1023                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1024                 goto done;
1025         }
1026
1027         /*
1028          * try to fragment the packet.  case 1-b and 3
1029          */
1030         if (mtu < IPV6_MMTU) {
1031                 /* path MTU cannot be less than IPV6_MMTU */
1032                 error = EMSGSIZE;
1033                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
1034                 goto bad;
1035         } else if (ip6->ip6_plen == 0) {
1036                 /* jumbo payload cannot be fragmented */
1037                 error = EMSGSIZE;
1038                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
1039                 goto bad;
1040         } else {
1041                 struct mbuf **mnext, *m_frgpart;
1042                 struct ip6_frag *ip6f;
1043                 u_int32_t id = htonl(ip6_randomid());
1044                 u_char nextproto;
1045
1046                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
1047
1048                 /*
1049                  * Too large for the destination or interface;
1050                  * fragment if possible.
1051                  * Must be able to put at least 8 bytes per fragment.
1052                  */
1053                 hlen = unfragpartlen;
1054                 if (mtu > IPV6_MAXPACKET)
1055                         mtu = IPV6_MAXPACKET;
1056
1057                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
1058                 if (len < 8) {
1059                         error = EMSGSIZE;
1060                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
1061                         goto bad;
1062                 }
1063
1064                 /*
1065                  * Verify that we have any chance at all of being able to queue
1066                  *      the packet or packet fragments
1067                  */
1068                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
1069                     < tlen  /* - hlen */)) {
1070                         error = ENOBUFS;
1071                         IP6STAT_INC(ip6s_odropped);
1072                         goto bad;
1073                 }
1074
1075
1076                 /*
1077                  * If the interface will not calculate checksums on
1078                  * fragmented packets, then do it here.
1079                  * XXX-BZ handle the hw offloading case.  Need flags.
1080                  */
1081                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1082                         in6_delayed_cksum(m, plen, hlen);
1083                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
1084                 }
1085 #ifdef SCTP
1086                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
1087                         sctp_delayed_cksum(m, hlen);
1088                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
1089                 }
1090 #endif
1091                 mnext = &m->m_nextpkt;
1092
1093                 /*
1094                  * Change the next header field of the last header in the
1095                  * unfragmentable part.
1096                  */
1097                 if (exthdrs.ip6e_rthdr) {
1098                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1099                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1100                 } else if (exthdrs.ip6e_dest1) {
1101                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1102                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1103                 } else if (exthdrs.ip6e_hbh) {
1104                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1105                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1106                 } else {
1107                         nextproto = ip6->ip6_nxt;
1108                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
1109                 }
1110
1111                 /*
1112                  * Loop through length of segment after first fragment,
1113                  * make new header and copy data of each part and link onto
1114                  * chain.
1115                  */
1116                 m0 = m;
1117                 for (off = hlen; off < tlen; off += len) {
1118                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
1119                         if (!m) {
1120                                 error = ENOBUFS;
1121                                 IP6STAT_INC(ip6s_odropped);
1122                                 goto sendorfree;
1123                         }
1124                         m->m_pkthdr.rcvif = NULL;
1125                         m->m_flags = m0->m_flags & M_COPYFLAGS; /* incl. FIB */
1126                         *mnext = m;
1127                         mnext = &m->m_nextpkt;
1128                         m->m_data += max_linkhdr;
1129                         mhip6 = mtod(m, struct ip6_hdr *);
1130                         *mhip6 = *ip6;
1131                         m->m_len = sizeof(*mhip6);
1132                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1133                         if (error) {
1134                                 IP6STAT_INC(ip6s_odropped);
1135                                 goto sendorfree;
1136                         }
1137                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1138                         if (off + len >= tlen)
1139                                 len = tlen - off;
1140                         else
1141                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1142                         mhip6->ip6_plen = htons((u_short)(len + hlen +
1143                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1144                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1145                                 error = ENOBUFS;
1146                                 IP6STAT_INC(ip6s_odropped);
1147                                 goto sendorfree;
1148                         }
1149                         m_cat(m, m_frgpart);
1150                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1151                         m->m_pkthdr.rcvif = NULL;
1152                         ip6f->ip6f_reserved = 0;
1153                         ip6f->ip6f_ident = id;
1154                         ip6f->ip6f_nxt = nextproto;
1155                         IP6STAT_INC(ip6s_ofragments);
1156                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1157                 }
1158
1159                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1160         }
1161
1162         /*
1163          * Remove leading garbages.
1164          */
1165 sendorfree:
1166         m = m0->m_nextpkt;
1167         m0->m_nextpkt = 0;
1168         m_freem(m0);
1169         for (m0 = m; m; m = m0) {
1170                 m0 = m->m_nextpkt;
1171                 m->m_nextpkt = 0;
1172                 if (error == 0) {
1173                         /* Record statistics for this interface address. */
1174                         if (ia) {
1175                                 ia->ia_ifa.if_opackets++;
1176                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1177                         }
1178                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1179                 } else
1180                         m_freem(m);
1181         }
1182
1183         if (error == 0)
1184                 IP6STAT_INC(ip6s_fragmented);
1185
1186 done:
1187         if (ro == &ip6route)
1188                 RO_RTFREE(ro);
1189         if (ro_pmtu == &ip6route)
1190                 RO_RTFREE(ro_pmtu);
1191 #ifdef IPSEC
1192         if (sp != NULL)
1193                 KEY_FREESP(&sp);
1194 #endif
1195
1196         return (error);
1197
1198 freehdrs:
1199         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1200         m_freem(exthdrs.ip6e_dest1);
1201         m_freem(exthdrs.ip6e_rthdr);
1202         m_freem(exthdrs.ip6e_dest2);
1203         /* FALLTHROUGH */
1204 bad:
1205         if (m)
1206                 m_freem(m);
1207         goto done;
1208 }
1209
1210 static int
1211 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1212 {
1213         struct mbuf *m;
1214
1215         if (hlen > MCLBYTES)
1216                 return (ENOBUFS); /* XXX */
1217
1218         MGET(m, M_DONTWAIT, MT_DATA);
1219         if (!m)
1220                 return (ENOBUFS);
1221
1222         if (hlen > MLEN) {
1223                 MCLGET(m, M_DONTWAIT);
1224                 if ((m->m_flags & M_EXT) == 0) {
1225                         m_free(m);
1226                         return (ENOBUFS);
1227                 }
1228         }
1229         m->m_len = hlen;
1230         if (hdr)
1231                 bcopy(hdr, mtod(m, caddr_t), hlen);
1232
1233         *mp = m;
1234         return (0);
1235 }
1236
1237 /*
1238  * Insert jumbo payload option.
1239  */
1240 static int
1241 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1242 {
1243         struct mbuf *mopt;
1244         u_char *optbuf;
1245         u_int32_t v;
1246
1247 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1248
1249         /*
1250          * If there is no hop-by-hop options header, allocate new one.
1251          * If there is one but it doesn't have enough space to store the
1252          * jumbo payload option, allocate a cluster to store the whole options.
1253          * Otherwise, use it to store the options.
1254          */
1255         if (exthdrs->ip6e_hbh == 0) {
1256                 MGET(mopt, M_DONTWAIT, MT_DATA);
1257                 if (mopt == 0)
1258                         return (ENOBUFS);
1259                 mopt->m_len = JUMBOOPTLEN;
1260                 optbuf = mtod(mopt, u_char *);
1261                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1262                 exthdrs->ip6e_hbh = mopt;
1263         } else {
1264                 struct ip6_hbh *hbh;
1265
1266                 mopt = exthdrs->ip6e_hbh;
1267                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1268                         /*
1269                          * XXX assumption:
1270                          * - exthdrs->ip6e_hbh is not referenced from places
1271                          *   other than exthdrs.
1272                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1273                          */
1274                         int oldoptlen = mopt->m_len;
1275                         struct mbuf *n;
1276
1277                         /*
1278                          * XXX: give up if the whole (new) hbh header does
1279                          * not fit even in an mbuf cluster.
1280                          */
1281                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1282                                 return (ENOBUFS);
1283
1284                         /*
1285                          * As a consequence, we must always prepare a cluster
1286                          * at this point.
1287                          */
1288                         MGET(n, M_DONTWAIT, MT_DATA);
1289                         if (n) {
1290                                 MCLGET(n, M_DONTWAIT);
1291                                 if ((n->m_flags & M_EXT) == 0) {
1292                                         m_freem(n);
1293                                         n = NULL;
1294                                 }
1295                         }
1296                         if (!n)
1297                                 return (ENOBUFS);
1298                         n->m_len = oldoptlen + JUMBOOPTLEN;
1299                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1300                             oldoptlen);
1301                         optbuf = mtod(n, caddr_t) + oldoptlen;
1302                         m_freem(mopt);
1303                         mopt = exthdrs->ip6e_hbh = n;
1304                 } else {
1305                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1306                         mopt->m_len += JUMBOOPTLEN;
1307                 }
1308                 optbuf[0] = IP6OPT_PADN;
1309                 optbuf[1] = 1;
1310
1311                 /*
1312                  * Adjust the header length according to the pad and
1313                  * the jumbo payload option.
1314                  */
1315                 hbh = mtod(mopt, struct ip6_hbh *);
1316                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1317         }
1318
1319         /* fill in the option. */
1320         optbuf[2] = IP6OPT_JUMBO;
1321         optbuf[3] = 4;
1322         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1323         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1324
1325         /* finally, adjust the packet header length */
1326         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1327
1328         return (0);
1329 #undef JUMBOOPTLEN
1330 }
1331
1332 /*
1333  * Insert fragment header and copy unfragmentable header portions.
1334  */
1335 static int
1336 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1337     struct ip6_frag **frghdrp)
1338 {
1339         struct mbuf *n, *mlast;
1340
1341         if (hlen > sizeof(struct ip6_hdr)) {
1342                 n = m_copym(m0, sizeof(struct ip6_hdr),
1343                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
1344                 if (n == 0)
1345                         return (ENOBUFS);
1346                 m->m_next = n;
1347         } else
1348                 n = m;
1349
1350         /* Search for the last mbuf of unfragmentable part. */
1351         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1352                 ;
1353
1354         if ((mlast->m_flags & M_EXT) == 0 &&
1355             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1356                 /* use the trailing space of the last mbuf for the fragment hdr */
1357                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1358                     mlast->m_len);
1359                 mlast->m_len += sizeof(struct ip6_frag);
1360                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1361         } else {
1362                 /* allocate a new mbuf for the fragment header */
1363                 struct mbuf *mfrg;
1364
1365                 MGET(mfrg, M_DONTWAIT, MT_DATA);
1366                 if (mfrg == 0)
1367                         return (ENOBUFS);
1368                 mfrg->m_len = sizeof(struct ip6_frag);
1369                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1370                 mlast->m_next = mfrg;
1371         }
1372
1373         return (0);
1374 }
1375
1376 static int
1377 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1378     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1379     int *alwaysfragp, u_int fibnum)
1380 {
1381         u_int32_t mtu = 0;
1382         int alwaysfrag = 0;
1383         int error = 0;
1384
1385         if (ro_pmtu != ro) {
1386                 /* The first hop and the final destination may differ. */
1387                 struct sockaddr_in6 *sa6_dst =
1388                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1389                 if (ro_pmtu->ro_rt &&
1390                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1391                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1392                         RTFREE(ro_pmtu->ro_rt);
1393                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
1394                 }
1395                 if (ro_pmtu->ro_rt == NULL) {
1396                         bzero(sa6_dst, sizeof(*sa6_dst));
1397                         sa6_dst->sin6_family = AF_INET6;
1398                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1399                         sa6_dst->sin6_addr = *dst;
1400
1401                         in6_rtalloc(ro_pmtu, fibnum);
1402                 }
1403         }
1404         if (ro_pmtu->ro_rt) {
1405                 u_int32_t ifmtu;
1406                 struct in_conninfo inc;
1407
1408                 bzero(&inc, sizeof(inc));
1409                 inc.inc_flags |= INC_ISIPV6;
1410                 inc.inc6_faddr = *dst;
1411
1412                 if (ifp == NULL)
1413                         ifp = ro_pmtu->ro_rt->rt_ifp;
1414                 ifmtu = IN6_LINKMTU(ifp);
1415                 mtu = tcp_hc_getmtu(&inc);
1416                 if (mtu)
1417                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
1418                 else
1419                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1420                 if (mtu == 0)
1421                         mtu = ifmtu;
1422                 else if (mtu < IPV6_MMTU) {
1423                         /*
1424                          * RFC2460 section 5, last paragraph:
1425                          * if we record ICMPv6 too big message with
1426                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1427                          * or smaller, with framgent header attached.
1428                          * (fragment header is needed regardless from the
1429                          * packet size, for translators to identify packets)
1430                          */
1431                         alwaysfrag = 1;
1432                         mtu = IPV6_MMTU;
1433                 } else if (mtu > ifmtu) {
1434                         /*
1435                          * The MTU on the route is larger than the MTU on
1436                          * the interface!  This shouldn't happen, unless the
1437                          * MTU of the interface has been changed after the
1438                          * interface was brought up.  Change the MTU in the
1439                          * route to match the interface MTU (as long as the
1440                          * field isn't locked).
1441                          */
1442                         mtu = ifmtu;
1443                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1444                 }
1445         } else if (ifp) {
1446                 mtu = IN6_LINKMTU(ifp);
1447         } else
1448                 error = EHOSTUNREACH; /* XXX */
1449
1450         *mtup = mtu;
1451         if (alwaysfragp)
1452                 *alwaysfragp = alwaysfrag;
1453         return (error);
1454 }
1455
1456 /*
1457  * IP6 socket option processing.
1458  */
1459 int
1460 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1461 {
1462         int optdatalen, uproto;
1463         void *optdata;
1464         struct inpcb *in6p = sotoinpcb(so);
1465         int error, optval;
1466         int level, op, optname;
1467         int optlen;
1468         struct thread *td;
1469
1470         level = sopt->sopt_level;
1471         op = sopt->sopt_dir;
1472         optname = sopt->sopt_name;
1473         optlen = sopt->sopt_valsize;
1474         td = sopt->sopt_td;
1475         error = 0;
1476         optval = 0;
1477         uproto = (int)so->so_proto->pr_protocol;
1478
1479         if (level != IPPROTO_IPV6) {
1480                 error = EINVAL;
1481
1482                 if (sopt->sopt_level == SOL_SOCKET &&
1483                     sopt->sopt_dir == SOPT_SET) {
1484                         switch (sopt->sopt_name) {
1485                         case SO_REUSEADDR:
1486                                 INP_WLOCK(in6p);
1487                                 if ((so->so_options & SO_REUSEADDR) != 0)
1488                                         in6p->inp_flags2 |= INP_REUSEADDR;
1489                                 else
1490                                         in6p->inp_flags2 &= ~INP_REUSEADDR;
1491                                 INP_WUNLOCK(in6p);
1492                                 error = 0;
1493                                 break;
1494                         case SO_REUSEPORT:
1495                                 INP_WLOCK(in6p);
1496                                 if ((so->so_options & SO_REUSEPORT) != 0)
1497                                         in6p->inp_flags2 |= INP_REUSEPORT;
1498                                 else
1499                                         in6p->inp_flags2 &= ~INP_REUSEPORT;
1500                                 INP_WUNLOCK(in6p);
1501                                 error = 0;
1502                                 break;
1503                         case SO_SETFIB:
1504                                 INP_WLOCK(in6p);
1505                                 in6p->inp_inc.inc_fibnum = so->so_fibnum;
1506                                 INP_WUNLOCK(in6p);
1507                                 error = 0;
1508                                 break;
1509                         default:
1510                                 break;
1511                         }
1512                 }
1513         } else {                /* level == IPPROTO_IPV6 */
1514                 switch (op) {
1515
1516                 case SOPT_SET:
1517                         switch (optname) {
1518                         case IPV6_2292PKTOPTIONS:
1519 #ifdef IPV6_PKTOPTIONS
1520                         case IPV6_PKTOPTIONS:
1521 #endif
1522                         {
1523                                 struct mbuf *m;
1524
1525                                 error = soopt_getm(sopt, &m); /* XXX */
1526                                 if (error != 0)
1527                                         break;
1528                                 error = soopt_mcopyin(sopt, m); /* XXX */
1529                                 if (error != 0)
1530                                         break;
1531                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1532                                                     m, so, sopt);
1533                                 m_freem(m); /* XXX */
1534                                 break;
1535                         }
1536
1537                         /*
1538                          * Use of some Hop-by-Hop options or some
1539                          * Destination options, might require special
1540                          * privilege.  That is, normal applications
1541                          * (without special privilege) might be forbidden
1542                          * from setting certain options in outgoing packets,
1543                          * and might never see certain options in received
1544                          * packets. [RFC 2292 Section 6]
1545                          * KAME specific note:
1546                          *  KAME prevents non-privileged users from sending or
1547                          *  receiving ANY hbh/dst options in order to avoid
1548                          *  overhead of parsing options in the kernel.
1549                          */
1550                         case IPV6_RECVHOPOPTS:
1551                         case IPV6_RECVDSTOPTS:
1552                         case IPV6_RECVRTHDRDSTOPTS:
1553                                 if (td != NULL) {
1554                                         error = priv_check(td,
1555                                             PRIV_NETINET_SETHDROPTS);
1556                                         if (error)
1557                                                 break;
1558                                 }
1559                                 /* FALLTHROUGH */
1560                         case IPV6_UNICAST_HOPS:
1561                         case IPV6_HOPLIMIT:
1562                         case IPV6_FAITH:
1563
1564                         case IPV6_RECVPKTINFO:
1565                         case IPV6_RECVHOPLIMIT:
1566                         case IPV6_RECVRTHDR:
1567                         case IPV6_RECVPATHMTU:
1568                         case IPV6_RECVTCLASS:
1569                         case IPV6_V6ONLY:
1570                         case IPV6_AUTOFLOWLABEL:
1571                         case IPV6_BINDANY:
1572                                 if (optname == IPV6_BINDANY && td != NULL) {
1573                                         error = priv_check(td,
1574                                             PRIV_NETINET_BINDANY);
1575                                         if (error)
1576                                                 break;
1577                                 }
1578
1579                                 if (optlen != sizeof(int)) {
1580                                         error = EINVAL;
1581                                         break;
1582                                 }
1583                                 error = sooptcopyin(sopt, &optval,
1584                                         sizeof optval, sizeof optval);
1585                                 if (error)
1586                                         break;
1587                                 switch (optname) {
1588
1589                                 case IPV6_UNICAST_HOPS:
1590                                         if (optval < -1 || optval >= 256)
1591                                                 error = EINVAL;
1592                                         else {
1593                                                 /* -1 = kernel default */
1594                                                 in6p->in6p_hops = optval;
1595                                                 if ((in6p->inp_vflag &
1596                                                      INP_IPV4) != 0)
1597                                                         in6p->inp_ip_ttl = optval;
1598                                         }
1599                                         break;
1600 #define OPTSET(bit) \
1601 do { \
1602         INP_WLOCK(in6p); \
1603         if (optval) \
1604                 in6p->inp_flags |= (bit); \
1605         else \
1606                 in6p->inp_flags &= ~(bit); \
1607         INP_WUNLOCK(in6p); \
1608 } while (/*CONSTCOND*/ 0)
1609 #define OPTSET2292(bit) \
1610 do { \
1611         INP_WLOCK(in6p); \
1612         in6p->inp_flags |= IN6P_RFC2292; \
1613         if (optval) \
1614                 in6p->inp_flags |= (bit); \
1615         else \
1616                 in6p->inp_flags &= ~(bit); \
1617         INP_WUNLOCK(in6p); \
1618 } while (/*CONSTCOND*/ 0)
1619 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1620
1621                                 case IPV6_RECVPKTINFO:
1622                                         /* cannot mix with RFC2292 */
1623                                         if (OPTBIT(IN6P_RFC2292)) {
1624                                                 error = EINVAL;
1625                                                 break;
1626                                         }
1627                                         OPTSET(IN6P_PKTINFO);
1628                                         break;
1629
1630                                 case IPV6_HOPLIMIT:
1631                                 {
1632                                         struct ip6_pktopts **optp;
1633
1634                                         /* cannot mix with RFC2292 */
1635                                         if (OPTBIT(IN6P_RFC2292)) {
1636                                                 error = EINVAL;
1637                                                 break;
1638                                         }
1639                                         optp = &in6p->in6p_outputopts;
1640                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1641                                             (u_char *)&optval, sizeof(optval),
1642                                             optp, (td != NULL) ? td->td_ucred :
1643                                             NULL, uproto);
1644                                         break;
1645                                 }
1646
1647                                 case IPV6_RECVHOPLIMIT:
1648                                         /* cannot mix with RFC2292 */
1649                                         if (OPTBIT(IN6P_RFC2292)) {
1650                                                 error = EINVAL;
1651                                                 break;
1652                                         }
1653                                         OPTSET(IN6P_HOPLIMIT);
1654                                         break;
1655
1656                                 case IPV6_RECVHOPOPTS:
1657                                         /* cannot mix with RFC2292 */
1658                                         if (OPTBIT(IN6P_RFC2292)) {
1659                                                 error = EINVAL;
1660                                                 break;
1661                                         }
1662                                         OPTSET(IN6P_HOPOPTS);
1663                                         break;
1664
1665                                 case IPV6_RECVDSTOPTS:
1666                                         /* cannot mix with RFC2292 */
1667                                         if (OPTBIT(IN6P_RFC2292)) {
1668                                                 error = EINVAL;
1669                                                 break;
1670                                         }
1671                                         OPTSET(IN6P_DSTOPTS);
1672                                         break;
1673
1674                                 case IPV6_RECVRTHDRDSTOPTS:
1675                                         /* cannot mix with RFC2292 */
1676                                         if (OPTBIT(IN6P_RFC2292)) {
1677                                                 error = EINVAL;
1678                                                 break;
1679                                         }
1680                                         OPTSET(IN6P_RTHDRDSTOPTS);
1681                                         break;
1682
1683                                 case IPV6_RECVRTHDR:
1684                                         /* cannot mix with RFC2292 */
1685                                         if (OPTBIT(IN6P_RFC2292)) {
1686                                                 error = EINVAL;
1687                                                 break;
1688                                         }
1689                                         OPTSET(IN6P_RTHDR);
1690                                         break;
1691
1692                                 case IPV6_FAITH:
1693                                         OPTSET(INP_FAITH);
1694                                         break;
1695
1696                                 case IPV6_RECVPATHMTU:
1697                                         /*
1698                                          * We ignore this option for TCP
1699                                          * sockets.
1700                                          * (RFC3542 leaves this case
1701                                          * unspecified.)
1702                                          */
1703                                         if (uproto != IPPROTO_TCP)
1704                                                 OPTSET(IN6P_MTU);
1705                                         break;
1706
1707                                 case IPV6_V6ONLY:
1708                                         /*
1709                                          * make setsockopt(IPV6_V6ONLY)
1710                                          * available only prior to bind(2).
1711                                          * see ipng mailing list, Jun 22 2001.
1712                                          */
1713                                         if (in6p->inp_lport ||
1714                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1715                                                 error = EINVAL;
1716                                                 break;
1717                                         }
1718                                         OPTSET(IN6P_IPV6_V6ONLY);
1719                                         if (optval)
1720                                                 in6p->inp_vflag &= ~INP_IPV4;
1721                                         else
1722                                                 in6p->inp_vflag |= INP_IPV4;
1723                                         break;
1724                                 case IPV6_RECVTCLASS:
1725                                         /* cannot mix with RFC2292 XXX */
1726                                         if (OPTBIT(IN6P_RFC2292)) {
1727                                                 error = EINVAL;
1728                                                 break;
1729                                         }
1730                                         OPTSET(IN6P_TCLASS);
1731                                         break;
1732                                 case IPV6_AUTOFLOWLABEL:
1733                                         OPTSET(IN6P_AUTOFLOWLABEL);
1734                                         break;
1735
1736                                 case IPV6_BINDANY:
1737                                         OPTSET(INP_BINDANY);
1738                                         break;
1739                                 }
1740                                 break;
1741
1742                         case IPV6_TCLASS:
1743                         case IPV6_DONTFRAG:
1744                         case IPV6_USE_MIN_MTU:
1745                         case IPV6_PREFER_TEMPADDR:
1746                                 if (optlen != sizeof(optval)) {
1747                                         error = EINVAL;
1748                                         break;
1749                                 }
1750                                 error = sooptcopyin(sopt, &optval,
1751                                         sizeof optval, sizeof optval);
1752                                 if (error)
1753                                         break;
1754                                 {
1755                                         struct ip6_pktopts **optp;
1756                                         optp = &in6p->in6p_outputopts;
1757                                         error = ip6_pcbopt(optname,
1758                                             (u_char *)&optval, sizeof(optval),
1759                                             optp, (td != NULL) ? td->td_ucred :
1760                                             NULL, uproto);
1761                                         break;
1762                                 }
1763
1764                         case IPV6_2292PKTINFO:
1765                         case IPV6_2292HOPLIMIT:
1766                         case IPV6_2292HOPOPTS:
1767                         case IPV6_2292DSTOPTS:
1768                         case IPV6_2292RTHDR:
1769                                 /* RFC 2292 */
1770                                 if (optlen != sizeof(int)) {
1771                                         error = EINVAL;
1772                                         break;
1773                                 }
1774                                 error = sooptcopyin(sopt, &optval,
1775                                         sizeof optval, sizeof optval);
1776                                 if (error)
1777                                         break;
1778                                 switch (optname) {
1779                                 case IPV6_2292PKTINFO:
1780                                         OPTSET2292(IN6P_PKTINFO);
1781                                         break;
1782                                 case IPV6_2292HOPLIMIT:
1783                                         OPTSET2292(IN6P_HOPLIMIT);
1784                                         break;
1785                                 case IPV6_2292HOPOPTS:
1786                                         /*
1787                                          * Check super-user privilege.
1788                                          * See comments for IPV6_RECVHOPOPTS.
1789                                          */
1790                                         if (td != NULL) {
1791                                                 error = priv_check(td,
1792                                                     PRIV_NETINET_SETHDROPTS);
1793                                                 if (error)
1794                                                         return (error);
1795                                         }
1796                                         OPTSET2292(IN6P_HOPOPTS);
1797                                         break;
1798                                 case IPV6_2292DSTOPTS:
1799                                         if (td != NULL) {
1800                                                 error = priv_check(td,
1801                                                     PRIV_NETINET_SETHDROPTS);
1802                                                 if (error)
1803                                                         return (error);
1804                                         }
1805                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1806                                         break;
1807                                 case IPV6_2292RTHDR:
1808                                         OPTSET2292(IN6P_RTHDR);
1809                                         break;
1810                                 }
1811                                 break;
1812                         case IPV6_PKTINFO:
1813                         case IPV6_HOPOPTS:
1814                         case IPV6_RTHDR:
1815                         case IPV6_DSTOPTS:
1816                         case IPV6_RTHDRDSTOPTS:
1817                         case IPV6_NEXTHOP:
1818                         {
1819                                 /* new advanced API (RFC3542) */
1820                                 u_char *optbuf;
1821                                 u_char optbuf_storage[MCLBYTES];
1822                                 int optlen;
1823                                 struct ip6_pktopts **optp;
1824
1825                                 /* cannot mix with RFC2292 */
1826                                 if (OPTBIT(IN6P_RFC2292)) {
1827                                         error = EINVAL;
1828                                         break;
1829                                 }
1830
1831                                 /*
1832                                  * We only ensure valsize is not too large
1833                                  * here.  Further validation will be done
1834                                  * later.
1835                                  */
1836                                 error = sooptcopyin(sopt, optbuf_storage,
1837                                     sizeof(optbuf_storage), 0);
1838                                 if (error)
1839                                         break;
1840                                 optlen = sopt->sopt_valsize;
1841                                 optbuf = optbuf_storage;
1842                                 optp = &in6p->in6p_outputopts;
1843                                 error = ip6_pcbopt(optname, optbuf, optlen,
1844                                     optp, (td != NULL) ? td->td_ucred : NULL,
1845                                     uproto);
1846                                 break;
1847                         }
1848 #undef OPTSET
1849
1850                         case IPV6_MULTICAST_IF:
1851                         case IPV6_MULTICAST_HOPS:
1852                         case IPV6_MULTICAST_LOOP:
1853                         case IPV6_JOIN_GROUP:
1854                         case IPV6_LEAVE_GROUP:
1855                         case IPV6_MSFILTER:
1856                         case MCAST_BLOCK_SOURCE:
1857                         case MCAST_UNBLOCK_SOURCE:
1858                         case MCAST_JOIN_GROUP:
1859                         case MCAST_LEAVE_GROUP:
1860                         case MCAST_JOIN_SOURCE_GROUP:
1861                         case MCAST_LEAVE_SOURCE_GROUP:
1862                                 error = ip6_setmoptions(in6p, sopt);
1863                                 break;
1864
1865                         case IPV6_PORTRANGE:
1866                                 error = sooptcopyin(sopt, &optval,
1867                                     sizeof optval, sizeof optval);
1868                                 if (error)
1869                                         break;
1870
1871                                 INP_WLOCK(in6p);
1872                                 switch (optval) {
1873                                 case IPV6_PORTRANGE_DEFAULT:
1874                                         in6p->inp_flags &= ~(INP_LOWPORT);
1875                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1876                                         break;
1877
1878                                 case IPV6_PORTRANGE_HIGH:
1879                                         in6p->inp_flags &= ~(INP_LOWPORT);
1880                                         in6p->inp_flags |= INP_HIGHPORT;
1881                                         break;
1882
1883                                 case IPV6_PORTRANGE_LOW:
1884                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1885                                         in6p->inp_flags |= INP_LOWPORT;
1886                                         break;
1887
1888                                 default:
1889                                         error = EINVAL;
1890                                         break;
1891                                 }
1892                                 INP_WUNLOCK(in6p);
1893                                 break;
1894
1895 #ifdef IPSEC
1896                         case IPV6_IPSEC_POLICY:
1897                         {
1898                                 caddr_t req;
1899                                 struct mbuf *m;
1900
1901                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1902                                         break;
1903                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1904                                         break;
1905                                 req = mtod(m, caddr_t);
1906                                 error = ipsec_set_policy(in6p, optname, req,
1907                                     m->m_len, (sopt->sopt_td != NULL) ?
1908                                     sopt->sopt_td->td_ucred : NULL);
1909                                 m_freem(m);
1910                                 break;
1911                         }
1912 #endif /* IPSEC */
1913
1914                         default:
1915                                 error = ENOPROTOOPT;
1916                                 break;
1917                         }
1918                         break;
1919
1920                 case SOPT_GET:
1921                         switch (optname) {
1922
1923                         case IPV6_2292PKTOPTIONS:
1924 #ifdef IPV6_PKTOPTIONS
1925                         case IPV6_PKTOPTIONS:
1926 #endif
1927                                 /*
1928                                  * RFC3542 (effectively) deprecated the
1929                                  * semantics of the 2292-style pktoptions.
1930                                  * Since it was not reliable in nature (i.e.,
1931                                  * applications had to expect the lack of some
1932                                  * information after all), it would make sense
1933                                  * to simplify this part by always returning
1934                                  * empty data.
1935                                  */
1936                                 sopt->sopt_valsize = 0;
1937                                 break;
1938
1939                         case IPV6_RECVHOPOPTS:
1940                         case IPV6_RECVDSTOPTS:
1941                         case IPV6_RECVRTHDRDSTOPTS:
1942                         case IPV6_UNICAST_HOPS:
1943                         case IPV6_RECVPKTINFO:
1944                         case IPV6_RECVHOPLIMIT:
1945                         case IPV6_RECVRTHDR:
1946                         case IPV6_RECVPATHMTU:
1947
1948                         case IPV6_FAITH:
1949                         case IPV6_V6ONLY:
1950                         case IPV6_PORTRANGE:
1951                         case IPV6_RECVTCLASS:
1952                         case IPV6_AUTOFLOWLABEL:
1953                         case IPV6_BINDANY:
1954                                 switch (optname) {
1955
1956                                 case IPV6_RECVHOPOPTS:
1957                                         optval = OPTBIT(IN6P_HOPOPTS);
1958                                         break;
1959
1960                                 case IPV6_RECVDSTOPTS:
1961                                         optval = OPTBIT(IN6P_DSTOPTS);
1962                                         break;
1963
1964                                 case IPV6_RECVRTHDRDSTOPTS:
1965                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1966                                         break;
1967
1968                                 case IPV6_UNICAST_HOPS:
1969                                         optval = in6p->in6p_hops;
1970                                         break;
1971
1972                                 case IPV6_RECVPKTINFO:
1973                                         optval = OPTBIT(IN6P_PKTINFO);
1974                                         break;
1975
1976                                 case IPV6_RECVHOPLIMIT:
1977                                         optval = OPTBIT(IN6P_HOPLIMIT);
1978                                         break;
1979
1980                                 case IPV6_RECVRTHDR:
1981                                         optval = OPTBIT(IN6P_RTHDR);
1982                                         break;
1983
1984                                 case IPV6_RECVPATHMTU:
1985                                         optval = OPTBIT(IN6P_MTU);
1986                                         break;
1987
1988                                 case IPV6_FAITH:
1989                                         optval = OPTBIT(INP_FAITH);
1990                                         break;
1991
1992                                 case IPV6_V6ONLY:
1993                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1994                                         break;
1995
1996                                 case IPV6_PORTRANGE:
1997                                     {
1998                                         int flags;
1999                                         flags = in6p->inp_flags;
2000                                         if (flags & INP_HIGHPORT)
2001                                                 optval = IPV6_PORTRANGE_HIGH;
2002                                         else if (flags & INP_LOWPORT)
2003                                                 optval = IPV6_PORTRANGE_LOW;
2004                                         else
2005                                                 optval = 0;
2006                                         break;
2007                                     }
2008                                 case IPV6_RECVTCLASS:
2009                                         optval = OPTBIT(IN6P_TCLASS);
2010                                         break;
2011
2012                                 case IPV6_AUTOFLOWLABEL:
2013                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2014                                         break;
2015
2016                                 case IPV6_BINDANY:
2017                                         optval = OPTBIT(INP_BINDANY);
2018                                         break;
2019                                 }
2020                                 if (error)
2021                                         break;
2022                                 error = sooptcopyout(sopt, &optval,
2023                                         sizeof optval);
2024                                 break;
2025
2026                         case IPV6_PATHMTU:
2027                         {
2028                                 u_long pmtu = 0;
2029                                 struct ip6_mtuinfo mtuinfo;
2030                                 struct route_in6 sro;
2031
2032                                 bzero(&sro, sizeof(sro));
2033
2034                                 if (!(so->so_state & SS_ISCONNECTED))
2035                                         return (ENOTCONN);
2036                                 /*
2037                                  * XXX: we dot not consider the case of source
2038                                  * routing, or optional information to specify
2039                                  * the outgoing interface.
2040                                  */
2041                                 error = ip6_getpmtu(&sro, NULL, NULL,
2042                                     &in6p->in6p_faddr, &pmtu, NULL,
2043                                     so->so_fibnum);
2044                                 if (sro.ro_rt)
2045                                         RTFREE(sro.ro_rt);
2046                                 if (error)
2047                                         break;
2048                                 if (pmtu > IPV6_MAXPACKET)
2049                                         pmtu = IPV6_MAXPACKET;
2050
2051                                 bzero(&mtuinfo, sizeof(mtuinfo));
2052                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2053                                 optdata = (void *)&mtuinfo;
2054                                 optdatalen = sizeof(mtuinfo);
2055                                 error = sooptcopyout(sopt, optdata,
2056                                     optdatalen);
2057                                 break;
2058                         }
2059
2060                         case IPV6_2292PKTINFO:
2061                         case IPV6_2292HOPLIMIT:
2062                         case IPV6_2292HOPOPTS:
2063                         case IPV6_2292RTHDR:
2064                         case IPV6_2292DSTOPTS:
2065                                 switch (optname) {
2066                                 case IPV6_2292PKTINFO:
2067                                         optval = OPTBIT(IN6P_PKTINFO);
2068                                         break;
2069                                 case IPV6_2292HOPLIMIT:
2070                                         optval = OPTBIT(IN6P_HOPLIMIT);
2071                                         break;
2072                                 case IPV6_2292HOPOPTS:
2073                                         optval = OPTBIT(IN6P_HOPOPTS);
2074                                         break;
2075                                 case IPV6_2292RTHDR:
2076                                         optval = OPTBIT(IN6P_RTHDR);
2077                                         break;
2078                                 case IPV6_2292DSTOPTS:
2079                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2080                                         break;
2081                                 }
2082                                 error = sooptcopyout(sopt, &optval,
2083                                     sizeof optval);
2084                                 break;
2085                         case IPV6_PKTINFO:
2086                         case IPV6_HOPOPTS:
2087                         case IPV6_RTHDR:
2088                         case IPV6_DSTOPTS:
2089                         case IPV6_RTHDRDSTOPTS:
2090                         case IPV6_NEXTHOP:
2091                         case IPV6_TCLASS:
2092                         case IPV6_DONTFRAG:
2093                         case IPV6_USE_MIN_MTU:
2094                         case IPV6_PREFER_TEMPADDR:
2095                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
2096                                     optname, sopt);
2097                                 break;
2098
2099                         case IPV6_MULTICAST_IF:
2100                         case IPV6_MULTICAST_HOPS:
2101                         case IPV6_MULTICAST_LOOP:
2102                         case IPV6_MSFILTER:
2103                                 error = ip6_getmoptions(in6p, sopt);
2104                                 break;
2105
2106 #ifdef IPSEC
2107                         case IPV6_IPSEC_POLICY:
2108                           {
2109                                 caddr_t req = NULL;
2110                                 size_t len = 0;
2111                                 struct mbuf *m = NULL;
2112                                 struct mbuf **mp = &m;
2113                                 size_t ovalsize = sopt->sopt_valsize;
2114                                 caddr_t oval = (caddr_t)sopt->sopt_val;
2115
2116                                 error = soopt_getm(sopt, &m); /* XXX */
2117                                 if (error != 0)
2118                                         break;
2119                                 error = soopt_mcopyin(sopt, m); /* XXX */
2120                                 if (error != 0)
2121                                         break;
2122                                 sopt->sopt_valsize = ovalsize;
2123                                 sopt->sopt_val = oval;
2124                                 if (m) {
2125                                         req = mtod(m, caddr_t);
2126                                         len = m->m_len;
2127                                 }
2128                                 error = ipsec_get_policy(in6p, req, len, mp);
2129                                 if (error == 0)
2130                                         error = soopt_mcopyout(sopt, m); /* XXX */
2131                                 if (error == 0 && m)
2132                                         m_freem(m);
2133                                 break;
2134                           }
2135 #endif /* IPSEC */
2136
2137                         default:
2138                                 error = ENOPROTOOPT;
2139                                 break;
2140                         }
2141                         break;
2142                 }
2143         }
2144         return (error);
2145 }
2146
2147 int
2148 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2149 {
2150         int error = 0, optval, optlen;
2151         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2152         struct inpcb *in6p = sotoinpcb(so);
2153         int level, op, optname;
2154
2155         level = sopt->sopt_level;
2156         op = sopt->sopt_dir;
2157         optname = sopt->sopt_name;
2158         optlen = sopt->sopt_valsize;
2159
2160         if (level != IPPROTO_IPV6) {
2161                 return (EINVAL);
2162         }
2163
2164         switch (optname) {
2165         case IPV6_CHECKSUM:
2166                 /*
2167                  * For ICMPv6 sockets, no modification allowed for checksum
2168                  * offset, permit "no change" values to help existing apps.
2169                  *
2170                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2171                  * for an ICMPv6 socket will fail."
2172                  * The current behavior does not meet RFC3542.
2173                  */
2174                 switch (op) {
2175                 case SOPT_SET:
2176                         if (optlen != sizeof(int)) {
2177                                 error = EINVAL;
2178                                 break;
2179                         }
2180                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2181                                             sizeof(optval));
2182                         if (error)
2183                                 break;
2184                         if ((optval % 2) != 0) {
2185                                 /* the API assumes even offset values */
2186                                 error = EINVAL;
2187                         } else if (so->so_proto->pr_protocol ==
2188                             IPPROTO_ICMPV6) {
2189                                 if (optval != icmp6off)
2190                                         error = EINVAL;
2191                         } else
2192                                 in6p->in6p_cksum = optval;
2193                         break;
2194
2195                 case SOPT_GET:
2196                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2197                                 optval = icmp6off;
2198                         else
2199                                 optval = in6p->in6p_cksum;
2200
2201                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2202                         break;
2203
2204                 default:
2205                         error = EINVAL;
2206                         break;
2207                 }
2208                 break;
2209
2210         default:
2211                 error = ENOPROTOOPT;
2212                 break;
2213         }
2214
2215         return (error);
2216 }
2217
2218 /*
2219  * Set up IP6 options in pcb for insertion in output packets or
2220  * specifying behavior of outgoing packets.
2221  */
2222 static int
2223 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2224     struct socket *so, struct sockopt *sopt)
2225 {
2226         struct ip6_pktopts *opt = *pktopt;
2227         int error = 0;
2228         struct thread *td = sopt->sopt_td;
2229
2230         /* turn off any old options. */
2231         if (opt) {
2232 #ifdef DIAGNOSTIC
2233                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2234                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2235                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2236                         printf("ip6_pcbopts: all specified options are cleared.\n");
2237 #endif
2238                 ip6_clearpktopts(opt, -1);
2239         } else
2240                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2241         *pktopt = NULL;
2242
2243         if (!m || m->m_len == 0) {
2244                 /*
2245                  * Only turning off any previous options, regardless of
2246                  * whether the opt is just created or given.
2247                  */
2248                 free(opt, M_IP6OPT);
2249                 return (0);
2250         }
2251
2252         /*  set options specified by user. */
2253         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2254             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2255                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2256                 free(opt, M_IP6OPT);
2257                 return (error);
2258         }
2259         *pktopt = opt;
2260         return (0);
2261 }
2262
2263 /*
2264  * initialize ip6_pktopts.  beware that there are non-zero default values in
2265  * the struct.
2266  */
2267 void
2268 ip6_initpktopts(struct ip6_pktopts *opt)
2269 {
2270
2271         bzero(opt, sizeof(*opt));
2272         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2273         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2274         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2275         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2276 }
2277
2278 static int
2279 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2280     struct ucred *cred, int uproto)
2281 {
2282         struct ip6_pktopts *opt;
2283
2284         if (*pktopt == NULL) {
2285                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2286                     M_WAITOK);
2287                 ip6_initpktopts(*pktopt);
2288         }
2289         opt = *pktopt;
2290
2291         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2292 }
2293
2294 static int
2295 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2296 {
2297         void *optdata = NULL;
2298         int optdatalen = 0;
2299         struct ip6_ext *ip6e;
2300         int error = 0;
2301         struct in6_pktinfo null_pktinfo;
2302         int deftclass = 0, on;
2303         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2304         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2305
2306         switch (optname) {
2307         case IPV6_PKTINFO:
2308                 if (pktopt && pktopt->ip6po_pktinfo)
2309                         optdata = (void *)pktopt->ip6po_pktinfo;
2310                 else {
2311                         /* XXX: we don't have to do this every time... */
2312                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2313                         optdata = (void *)&null_pktinfo;
2314                 }
2315                 optdatalen = sizeof(struct in6_pktinfo);
2316                 break;
2317         case IPV6_TCLASS:
2318                 if (pktopt && pktopt->ip6po_tclass >= 0)
2319                         optdata = (void *)&pktopt->ip6po_tclass;
2320                 else
2321                         optdata = (void *)&deftclass;
2322                 optdatalen = sizeof(int);
2323                 break;
2324         case IPV6_HOPOPTS:
2325                 if (pktopt && pktopt->ip6po_hbh) {
2326                         optdata = (void *)pktopt->ip6po_hbh;
2327                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2328                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2329                 }
2330                 break;
2331         case IPV6_RTHDR:
2332                 if (pktopt && pktopt->ip6po_rthdr) {
2333                         optdata = (void *)pktopt->ip6po_rthdr;
2334                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2335                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2336                 }
2337                 break;
2338         case IPV6_RTHDRDSTOPTS:
2339                 if (pktopt && pktopt->ip6po_dest1) {
2340                         optdata = (void *)pktopt->ip6po_dest1;
2341                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2342                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2343                 }
2344                 break;
2345         case IPV6_DSTOPTS:
2346                 if (pktopt && pktopt->ip6po_dest2) {
2347                         optdata = (void *)pktopt->ip6po_dest2;
2348                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2349                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2350                 }
2351                 break;
2352         case IPV6_NEXTHOP:
2353                 if (pktopt && pktopt->ip6po_nexthop) {
2354                         optdata = (void *)pktopt->ip6po_nexthop;
2355                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2356                 }
2357                 break;
2358         case IPV6_USE_MIN_MTU:
2359                 if (pktopt)
2360                         optdata = (void *)&pktopt->ip6po_minmtu;
2361                 else
2362                         optdata = (void *)&defminmtu;
2363                 optdatalen = sizeof(int);
2364                 break;
2365         case IPV6_DONTFRAG:
2366                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2367                         on = 1;
2368                 else
2369                         on = 0;
2370                 optdata = (void *)&on;
2371                 optdatalen = sizeof(on);
2372                 break;
2373         case IPV6_PREFER_TEMPADDR:
2374                 if (pktopt)
2375                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2376                 else
2377                         optdata = (void *)&defpreftemp;
2378                 optdatalen = sizeof(int);
2379                 break;
2380         default:                /* should not happen */
2381 #ifdef DIAGNOSTIC
2382                 panic("ip6_getpcbopt: unexpected option\n");
2383 #endif
2384                 return (ENOPROTOOPT);
2385         }
2386
2387         error = sooptcopyout(sopt, optdata, optdatalen);
2388
2389         return (error);
2390 }
2391
2392 void
2393 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2394 {
2395         if (pktopt == NULL)
2396                 return;
2397
2398         if (optname == -1 || optname == IPV6_PKTINFO) {
2399                 if (pktopt->ip6po_pktinfo)
2400                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2401                 pktopt->ip6po_pktinfo = NULL;
2402         }
2403         if (optname == -1 || optname == IPV6_HOPLIMIT)
2404                 pktopt->ip6po_hlim = -1;
2405         if (optname == -1 || optname == IPV6_TCLASS)
2406                 pktopt->ip6po_tclass = -1;
2407         if (optname == -1 || optname == IPV6_NEXTHOP) {
2408                 if (pktopt->ip6po_nextroute.ro_rt) {
2409                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2410                         pktopt->ip6po_nextroute.ro_rt = NULL;
2411                 }
2412                 if (pktopt->ip6po_nexthop)
2413                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2414                 pktopt->ip6po_nexthop = NULL;
2415         }
2416         if (optname == -1 || optname == IPV6_HOPOPTS) {
2417                 if (pktopt->ip6po_hbh)
2418                         free(pktopt->ip6po_hbh, M_IP6OPT);
2419                 pktopt->ip6po_hbh = NULL;
2420         }
2421         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2422                 if (pktopt->ip6po_dest1)
2423                         free(pktopt->ip6po_dest1, M_IP6OPT);
2424                 pktopt->ip6po_dest1 = NULL;
2425         }
2426         if (optname == -1 || optname == IPV6_RTHDR) {
2427                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2428                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2429                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2430                 if (pktopt->ip6po_route.ro_rt) {
2431                         RTFREE(pktopt->ip6po_route.ro_rt);
2432                         pktopt->ip6po_route.ro_rt = NULL;
2433                 }
2434         }
2435         if (optname == -1 || optname == IPV6_DSTOPTS) {
2436                 if (pktopt->ip6po_dest2)
2437                         free(pktopt->ip6po_dest2, M_IP6OPT);
2438                 pktopt->ip6po_dest2 = NULL;
2439         }
2440 }
2441
2442 #define PKTOPT_EXTHDRCPY(type) \
2443 do {\
2444         if (src->type) {\
2445                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2446                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2447                 if (dst->type == NULL && canwait == M_NOWAIT)\
2448                         goto bad;\
2449                 bcopy(src->type, dst->type, hlen);\
2450         }\
2451 } while (/*CONSTCOND*/ 0)
2452
2453 static int
2454 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2455 {
2456         if (dst == NULL || src == NULL)  {
2457                 printf("ip6_clearpktopts: invalid argument\n");
2458                 return (EINVAL);
2459         }
2460
2461         dst->ip6po_hlim = src->ip6po_hlim;
2462         dst->ip6po_tclass = src->ip6po_tclass;
2463         dst->ip6po_flags = src->ip6po_flags;
2464         dst->ip6po_minmtu = src->ip6po_minmtu;
2465         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2466         if (src->ip6po_pktinfo) {
2467                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2468                     M_IP6OPT, canwait);
2469                 if (dst->ip6po_pktinfo == NULL)
2470                         goto bad;
2471                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2472         }
2473         if (src->ip6po_nexthop) {
2474                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2475                     M_IP6OPT, canwait);
2476                 if (dst->ip6po_nexthop == NULL)
2477                         goto bad;
2478                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2479                     src->ip6po_nexthop->sa_len);
2480         }
2481         PKTOPT_EXTHDRCPY(ip6po_hbh);
2482         PKTOPT_EXTHDRCPY(ip6po_dest1);
2483         PKTOPT_EXTHDRCPY(ip6po_dest2);
2484         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2485         return (0);
2486
2487   bad:
2488         ip6_clearpktopts(dst, -1);
2489         return (ENOBUFS);
2490 }
2491 #undef PKTOPT_EXTHDRCPY
2492
2493 struct ip6_pktopts *
2494 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2495 {
2496         int error;
2497         struct ip6_pktopts *dst;
2498
2499         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2500         if (dst == NULL)
2501                 return (NULL);
2502         ip6_initpktopts(dst);
2503
2504         if ((error = copypktopts(dst, src, canwait)) != 0) {
2505                 free(dst, M_IP6OPT);
2506                 return (NULL);
2507         }
2508
2509         return (dst);
2510 }
2511
2512 void
2513 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2514 {
2515         if (pktopt == NULL)
2516                 return;
2517
2518         ip6_clearpktopts(pktopt, -1);
2519
2520         free(pktopt, M_IP6OPT);
2521 }
2522
2523 /*
2524  * Set IPv6 outgoing packet options based on advanced API.
2525  */
2526 int
2527 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2528     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2529 {
2530         struct cmsghdr *cm = 0;
2531
2532         if (control == NULL || opt == NULL)
2533                 return (EINVAL);
2534
2535         ip6_initpktopts(opt);
2536         if (stickyopt) {
2537                 int error;
2538
2539                 /*
2540                  * If stickyopt is provided, make a local copy of the options
2541                  * for this particular packet, then override them by ancillary
2542                  * objects.
2543                  * XXX: copypktopts() does not copy the cached route to a next
2544                  * hop (if any).  This is not very good in terms of efficiency,
2545                  * but we can allow this since this option should be rarely
2546                  * used.
2547                  */
2548                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2549                         return (error);
2550         }
2551
2552         /*
2553          * XXX: Currently, we assume all the optional information is stored
2554          * in a single mbuf.
2555          */
2556         if (control->m_next)
2557                 return (EINVAL);
2558
2559         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2560             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2561                 int error;
2562
2563                 if (control->m_len < CMSG_LEN(0))
2564                         return (EINVAL);
2565
2566                 cm = mtod(control, struct cmsghdr *);
2567                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2568                         return (EINVAL);
2569                 if (cm->cmsg_level != IPPROTO_IPV6)
2570                         continue;
2571
2572                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2573                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2574                 if (error)
2575                         return (error);
2576         }
2577
2578         return (0);
2579 }
2580
2581 /*
2582  * Set a particular packet option, as a sticky option or an ancillary data
2583  * item.  "len" can be 0 only when it's a sticky option.
2584  * We have 4 cases of combination of "sticky" and "cmsg":
2585  * "sticky=0, cmsg=0": impossible
2586  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2587  * "sticky=1, cmsg=0": RFC3542 socket option
2588  * "sticky=1, cmsg=1": RFC2292 socket option
2589  */
2590 static int
2591 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2592     struct ucred *cred, int sticky, int cmsg, int uproto)
2593 {
2594         int minmtupolicy, preftemp;
2595         int error;
2596
2597         if (!sticky && !cmsg) {
2598 #ifdef DIAGNOSTIC
2599                 printf("ip6_setpktopt: impossible case\n");
2600 #endif
2601                 return (EINVAL);
2602         }
2603
2604         /*
2605          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2606          * not be specified in the context of RFC3542.  Conversely,
2607          * RFC3542 types should not be specified in the context of RFC2292.
2608          */
2609         if (!cmsg) {
2610                 switch (optname) {
2611                 case IPV6_2292PKTINFO:
2612                 case IPV6_2292HOPLIMIT:
2613                 case IPV6_2292NEXTHOP:
2614                 case IPV6_2292HOPOPTS:
2615                 case IPV6_2292DSTOPTS:
2616                 case IPV6_2292RTHDR:
2617                 case IPV6_2292PKTOPTIONS:
2618                         return (ENOPROTOOPT);
2619                 }
2620         }
2621         if (sticky && cmsg) {
2622                 switch (optname) {
2623                 case IPV6_PKTINFO:
2624                 case IPV6_HOPLIMIT:
2625                 case IPV6_NEXTHOP:
2626                 case IPV6_HOPOPTS:
2627                 case IPV6_DSTOPTS:
2628                 case IPV6_RTHDRDSTOPTS:
2629                 case IPV6_RTHDR:
2630                 case IPV6_USE_MIN_MTU:
2631                 case IPV6_DONTFRAG:
2632                 case IPV6_TCLASS:
2633                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2634                         return (ENOPROTOOPT);
2635                 }
2636         }
2637
2638         switch (optname) {
2639         case IPV6_2292PKTINFO:
2640         case IPV6_PKTINFO:
2641         {
2642                 struct ifnet *ifp = NULL;
2643                 struct in6_pktinfo *pktinfo;
2644
2645                 if (len != sizeof(struct in6_pktinfo))
2646                         return (EINVAL);
2647
2648                 pktinfo = (struct in6_pktinfo *)buf;
2649
2650                 /*
2651                  * An application can clear any sticky IPV6_PKTINFO option by
2652                  * doing a "regular" setsockopt with ipi6_addr being
2653                  * in6addr_any and ipi6_ifindex being zero.
2654                  * [RFC 3542, Section 6]
2655                  */
2656                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2657                     pktinfo->ipi6_ifindex == 0 &&
2658                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2659                         ip6_clearpktopts(opt, optname);
2660                         break;
2661                 }
2662
2663                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2664                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2665                         return (EINVAL);
2666                 }
2667
2668                 /* validate the interface index if specified. */
2669                 if (pktinfo->ipi6_ifindex > V_if_index ||
2670                     pktinfo->ipi6_ifindex < 0) {
2671                          return (ENXIO);
2672                 }
2673                 if (pktinfo->ipi6_ifindex) {
2674                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2675                         if (ifp == NULL)
2676                                 return (ENXIO);
2677                 }
2678
2679                 /*
2680                  * We store the address anyway, and let in6_selectsrc()
2681                  * validate the specified address.  This is because ipi6_addr
2682                  * may not have enough information about its scope zone, and
2683                  * we may need additional information (such as outgoing
2684                  * interface or the scope zone of a destination address) to
2685                  * disambiguate the scope.
2686                  * XXX: the delay of the validation may confuse the
2687                  * application when it is used as a sticky option.
2688                  */
2689                 if (opt->ip6po_pktinfo == NULL) {
2690                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2691                             M_IP6OPT, M_NOWAIT);
2692                         if (opt->ip6po_pktinfo == NULL)
2693                                 return (ENOBUFS);
2694                 }
2695                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2696                 break;
2697         }
2698
2699         case IPV6_2292HOPLIMIT:
2700         case IPV6_HOPLIMIT:
2701         {
2702                 int *hlimp;
2703
2704                 /*
2705                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2706                  * to simplify the ordering among hoplimit options.
2707                  */
2708                 if (optname == IPV6_HOPLIMIT && sticky)
2709                         return (ENOPROTOOPT);
2710
2711                 if (len != sizeof(int))
2712                         return (EINVAL);
2713                 hlimp = (int *)buf;
2714                 if (*hlimp < -1 || *hlimp > 255)
2715                         return (EINVAL);
2716
2717                 opt->ip6po_hlim = *hlimp;
2718                 break;
2719         }
2720
2721         case IPV6_TCLASS:
2722         {
2723                 int tclass;
2724
2725                 if (len != sizeof(int))
2726                         return (EINVAL);
2727                 tclass = *(int *)buf;
2728                 if (tclass < -1 || tclass > 255)
2729                         return (EINVAL);
2730
2731                 opt->ip6po_tclass = tclass;
2732                 break;
2733         }
2734
2735         case IPV6_2292NEXTHOP:
2736         case IPV6_NEXTHOP:
2737                 if (cred != NULL) {
2738                         error = priv_check_cred(cred,
2739                             PRIV_NETINET_SETHDROPTS, 0);
2740                         if (error)
2741                                 return (error);
2742                 }
2743
2744                 if (len == 0) { /* just remove the option */
2745                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2746                         break;
2747                 }
2748
2749                 /* check if cmsg_len is large enough for sa_len */
2750                 if (len < sizeof(struct sockaddr) || len < *buf)
2751                         return (EINVAL);
2752
2753                 switch (((struct sockaddr *)buf)->sa_family) {
2754                 case AF_INET6:
2755                 {
2756                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2757                         int error;
2758
2759                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2760                                 return (EINVAL);
2761
2762                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2763                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2764                                 return (EINVAL);
2765                         }
2766                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2767                             != 0) {
2768                                 return (error);
2769                         }
2770                         break;
2771                 }
2772                 case AF_LINK:   /* should eventually be supported */
2773                 default:
2774                         return (EAFNOSUPPORT);
2775                 }
2776
2777                 /* turn off the previous option, then set the new option. */
2778                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2779                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2780                 if (opt->ip6po_nexthop == NULL)
2781                         return (ENOBUFS);
2782                 bcopy(buf, opt->ip6po_nexthop, *buf);
2783                 break;
2784
2785         case IPV6_2292HOPOPTS:
2786         case IPV6_HOPOPTS:
2787         {
2788                 struct ip6_hbh *hbh;
2789                 int hbhlen;
2790
2791                 /*
2792                  * XXX: We don't allow a non-privileged user to set ANY HbH
2793                  * options, since per-option restriction has too much
2794                  * overhead.
2795                  */
2796                 if (cred != NULL) {
2797                         error = priv_check_cred(cred,
2798                             PRIV_NETINET_SETHDROPTS, 0);
2799                         if (error)
2800                                 return (error);
2801                 }
2802
2803                 if (len == 0) {
2804                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2805                         break;  /* just remove the option */
2806                 }
2807
2808                 /* message length validation */
2809                 if (len < sizeof(struct ip6_hbh))
2810                         return (EINVAL);
2811                 hbh = (struct ip6_hbh *)buf;
2812                 hbhlen = (hbh->ip6h_len + 1) << 3;
2813                 if (len != hbhlen)
2814                         return (EINVAL);
2815
2816                 /* turn off the previous option, then set the new option. */
2817                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2818                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2819                 if (opt->ip6po_hbh == NULL)
2820                         return (ENOBUFS);
2821                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2822
2823                 break;
2824         }
2825
2826         case IPV6_2292DSTOPTS:
2827         case IPV6_DSTOPTS:
2828         case IPV6_RTHDRDSTOPTS:
2829         {
2830                 struct ip6_dest *dest, **newdest = NULL;
2831                 int destlen;
2832
2833                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2834                         error = priv_check_cred(cred,
2835                             PRIV_NETINET_SETHDROPTS, 0);
2836                         if (error)
2837                                 return (error);
2838                 }
2839
2840                 if (len == 0) {
2841                         ip6_clearpktopts(opt, optname);
2842                         break;  /* just remove the option */
2843                 }
2844
2845                 /* message length validation */
2846                 if (len < sizeof(struct ip6_dest))
2847                         return (EINVAL);
2848                 dest = (struct ip6_dest *)buf;
2849                 destlen = (dest->ip6d_len + 1) << 3;
2850                 if (len != destlen)
2851                         return (EINVAL);
2852
2853                 /*
2854                  * Determine the position that the destination options header
2855                  * should be inserted; before or after the routing header.
2856                  */
2857                 switch (optname) {
2858                 case IPV6_2292DSTOPTS:
2859                         /*
2860                          * The old advacned API is ambiguous on this point.
2861                          * Our approach is to determine the position based
2862                          * according to the existence of a routing header.
2863                          * Note, however, that this depends on the order of the
2864                          * extension headers in the ancillary data; the 1st
2865                          * part of the destination options header must appear
2866                          * before the routing header in the ancillary data,
2867                          * too.
2868                          * RFC3542 solved the ambiguity by introducing
2869                          * separate ancillary data or option types.
2870                          */
2871                         if (opt->ip6po_rthdr == NULL)
2872                                 newdest = &opt->ip6po_dest1;
2873                         else
2874                                 newdest = &opt->ip6po_dest2;
2875                         break;
2876                 case IPV6_RTHDRDSTOPTS:
2877                         newdest = &opt->ip6po_dest1;
2878                         break;
2879                 case IPV6_DSTOPTS:
2880                         newdest = &opt->ip6po_dest2;
2881                         break;
2882                 }
2883
2884                 /* turn off the previous option, then set the new option. */
2885                 ip6_clearpktopts(opt, optname);
2886                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2887                 if (*newdest == NULL)
2888                         return (ENOBUFS);
2889                 bcopy(dest, *newdest, destlen);
2890
2891                 break;
2892         }
2893
2894         case IPV6_2292RTHDR:
2895         case IPV6_RTHDR:
2896         {
2897                 struct ip6_rthdr *rth;
2898                 int rthlen;
2899
2900                 if (len == 0) {
2901                         ip6_clearpktopts(opt, IPV6_RTHDR);
2902                         break;  /* just remove the option */
2903                 }
2904
2905                 /* message length validation */
2906                 if (len < sizeof(struct ip6_rthdr))
2907                         return (EINVAL);
2908                 rth = (struct ip6_rthdr *)buf;
2909                 rthlen = (rth->ip6r_len + 1) << 3;
2910                 if (len != rthlen)
2911                         return (EINVAL);
2912
2913                 switch (rth->ip6r_type) {
2914                 case IPV6_RTHDR_TYPE_0:
2915                         if (rth->ip6r_len == 0) /* must contain one addr */
2916                                 return (EINVAL);
2917                         if (rth->ip6r_len % 2) /* length must be even */
2918                                 return (EINVAL);
2919                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2920                                 return (EINVAL);
2921                         break;
2922                 default:
2923                         return (EINVAL);        /* not supported */
2924                 }
2925
2926                 /* turn off the previous option */
2927                 ip6_clearpktopts(opt, IPV6_RTHDR);
2928                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2929                 if (opt->ip6po_rthdr == NULL)
2930                         return (ENOBUFS);
2931                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2932
2933                 break;
2934         }
2935
2936         case IPV6_USE_MIN_MTU:
2937                 if (len != sizeof(int))
2938                         return (EINVAL);
2939                 minmtupolicy = *(int *)buf;
2940                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2941                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2942                     minmtupolicy != IP6PO_MINMTU_ALL) {
2943                         return (EINVAL);
2944                 }
2945                 opt->ip6po_minmtu = minmtupolicy;
2946                 break;
2947
2948         case IPV6_DONTFRAG:
2949                 if (len != sizeof(int))
2950                         return (EINVAL);
2951
2952                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2953                         /*
2954                          * we ignore this option for TCP sockets.
2955                          * (RFC3542 leaves this case unspecified.)
2956                          */
2957                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2958                 } else
2959                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2960                 break;
2961
2962         case IPV6_PREFER_TEMPADDR:
2963                 if (len != sizeof(int))
2964                         return (EINVAL);
2965                 preftemp = *(int *)buf;
2966                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2967                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2968                     preftemp != IP6PO_TEMPADDR_PREFER) {
2969                         return (EINVAL);
2970                 }
2971                 opt->ip6po_prefer_tempaddr = preftemp;
2972                 break;
2973
2974         default:
2975                 return (ENOPROTOOPT);
2976         } /* end of switch */
2977
2978         return (0);
2979 }
2980
2981 /*
2982  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2983  * packet to the input queue of a specified interface.  Note that this
2984  * calls the output routine of the loopback "driver", but with an interface
2985  * pointer that might NOT be &loif -- easier than replicating that code here.
2986  */
2987 void
2988 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2989 {
2990         struct mbuf *copym;
2991         struct ip6_hdr *ip6;
2992
2993         copym = m_copy(m, 0, M_COPYALL);
2994         if (copym == NULL)
2995                 return;
2996
2997         /*
2998          * Make sure to deep-copy IPv6 header portion in case the data
2999          * is in an mbuf cluster, so that we can safely override the IPv6
3000          * header portion later.
3001          */
3002         if ((copym->m_flags & M_EXT) != 0 ||
3003             copym->m_len < sizeof(struct ip6_hdr)) {
3004                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3005                 if (copym == NULL)
3006                         return;
3007         }
3008         ip6 = mtod(copym, struct ip6_hdr *);
3009         /*
3010          * clear embedded scope identifiers if necessary.
3011          * in6_clearscope will touch the addresses only when necessary.
3012          */
3013         in6_clearscope(&ip6->ip6_src);
3014         in6_clearscope(&ip6->ip6_dst);
3015         if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3016                 copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3017                     CSUM_PSEUDO_HDR;
3018                 copym->m_pkthdr.csum_data = 0xffff;
3019         }
3020         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
3021 }
3022
3023 /*
3024  * Chop IPv6 header off from the payload.
3025  */
3026 static int
3027 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3028 {
3029         struct mbuf *mh;
3030         struct ip6_hdr *ip6;
3031
3032         ip6 = mtod(m, struct ip6_hdr *);
3033         if (m->m_len > sizeof(*ip6)) {
3034                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
3035                 if (mh == 0) {
3036                         m_freem(m);
3037                         return ENOBUFS;
3038                 }
3039                 M_MOVE_PKTHDR(mh, m);
3040                 MH_ALIGN(mh, sizeof(*ip6));
3041                 m->m_len -= sizeof(*ip6);
3042                 m->m_data += sizeof(*ip6);
3043                 mh->m_next = m;
3044                 m = mh;
3045                 m->m_len = sizeof(*ip6);
3046                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3047         }
3048         exthdrs->ip6e_ip6 = m;
3049         return 0;
3050 }
3051
3052 /*
3053  * Compute IPv6 extension header length.
3054  */
3055 int
3056 ip6_optlen(struct inpcb *in6p)
3057 {
3058         int len;
3059
3060         if (!in6p->in6p_outputopts)
3061                 return 0;
3062
3063         len = 0;
3064 #define elen(x) \
3065     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3066
3067         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3068         if (in6p->in6p_outputopts->ip6po_rthdr)
3069                 /* dest1 is valid with rthdr only */
3070                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3071         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3072         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3073         return len;
3074 #undef elen
3075 }