sys/netinet6/ip6_output.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
  32  */
  33
  34 /*-
  35  * Copyright (c) 1982, 1986, 1988, 1990, 1993
  36  *      The Regents of the University of California.  All rights reserved.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  63  */
  64
  65 #include <sys/cdefs.h>
  66 __FBSDID("$FreeBSD$");
  67
  68 #include "opt_inet.h"
  69 #include "opt_inet6.h"
  70 #include "opt_ratelimit.h"
  71 #include "opt_ipsec.h"
  72 #include "opt_sctp.h"
  73 #include "opt_route.h"
  74 #include "opt_rss.h"
  75
  76 #include <sys/param.h>
  77 #include <sys/kernel.h>
  78 #include <sys/malloc.h>
  79 #include <sys/mbuf.h>
  80 #include <sys/errno.h>
  81 #include <sys/priv.h>
  82 #include <sys/proc.h>
  83 #include <sys/protosw.h>
  84 #include <sys/socket.h>
  85 #include <sys/socketvar.h>
  86 #include <sys/syslog.h>
  87 #include <sys/ucred.h>
  88
  89 #include <machine/in_cksum.h>
  90
  91 #include <net/if.h>
  92 #include <net/if_var.h>
  93 #include <net/if_llatbl.h>
  94 #include <net/netisr.h>
  95 #include <net/route.h>
  96 #include <net/pfil.h>
  97 #include <net/rss_config.h>
  98 #include <net/vnet.h>
  99
 100 #include <netinet/in.h>
 101 #include <netinet/in_var.h>
 102 #include <netinet/ip_var.h>
 103 #include <netinet6/in6_fib.h>
 104 #include <netinet6/in6_var.h>
 105 #include <netinet/ip6.h>
 106 #include <netinet/icmp6.h>
 107 #include <netinet6/ip6_var.h>
 108 #include <netinet/in_pcb.h>
 109 #include <netinet/tcp_var.h>
 110 #include <netinet6/nd6.h>
 111 #include <netinet6/in6_rss.h>
 112
 113 #include <netipsec/ipsec_support.h>
 114 #ifdef SCTP
 115 #include <netinet/sctp.h>
 116 #include <netinet/sctp_crc32.h>
 117 #endif
 118
 119 #include <netinet6/ip6protosw.h>
 120 #include <netinet6/scope6_var.h>
 121
 122 extern int in6_mcast_loop;
 123
 124 struct ip6_exthdrs {
 125         struct mbuf *ip6e_ip6;
 126         struct mbuf *ip6e_hbh;
 127         struct mbuf *ip6e_dest1;
 128         struct mbuf *ip6e_rthdr;
 129         struct mbuf *ip6e_dest2;
 130 };
 131
 132 static MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
 133
 134 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
 135                            struct ucred *, int);
 136 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
 137         struct socket *, struct sockopt *);
 138 static int ip6_getpcbopt(struct inpcb *, int, struct sockopt *);
 139 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
 140         struct ucred *, int, int, int);
 141
 142 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 143 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
 144         struct ip6_frag **);
 145 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 146 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 147 static int ip6_getpmtu(struct route_in6 *, int,
 148         struct ifnet *, const struct in6_addr *, u_long *, int *, u_int,
 149         u_int);
 150 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
 151         u_long *, int *, u_int);
 152 static int ip6_getpmtu_ctl(u_int, const struct in6_addr *, u_long *);
 153 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 154
 155
 156 /*
 157  * Make an extension header from option data.  hp is the source, and
 158  * mp is the destination.
 159  */
 160 #define MAKE_EXTHDR(hp, mp)                                             \
 161     do {                                                                \
 162         if (hp) {                                                       \
 163                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 164                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 165                     ((eh)->ip6e_len + 1) << 3);                         \
 166                 if (error)                                              \
 167                         goto freehdrs;                                  \
 168         }                                                               \
 169     } while (/*CONSTCOND*/ 0)
 170
 171 /*
 172  * Form a chain of extension headers.
 173  * m is the extension header mbuf
 174  * mp is the previous mbuf in the chain
 175  * p is the next header
 176  * i is the type of option.
 177  */
 178 #define MAKE_CHAIN(m, mp, p, i)\
 179     do {\
 180         if (m) {\
 181                 if (!hdrsplit) \
 182                         panic("assumption failed: hdr not split"); \
 183                 *mtod((m), u_char *) = *(p);\
 184                 *(p) = (i);\
 185                 p = mtod((m), u_char *);\
 186                 (m)->m_next = (mp)->m_next;\
 187                 (mp)->m_next = (m);\
 188                 (mp) = (m);\
 189         }\
 190     } while (/*CONSTCOND*/ 0)
 191
 192 void
 193 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
 194 {
 195         u_short csum;
 196
 197         csum = in_cksum_skip(m, offset + plen, offset);
 198         if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
 199                 csum = 0xffff;
 200         offset += m->m_pkthdr.csum_data;        /* checksum offset */
 201
 202         if (offset + sizeof(csum) > m->m_len)
 203                 m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
 204         else
 205                 *(u_short *)mtodo(m, offset) = csum;
 206 }
 207
 208 int
 209 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
 210     int fraglen , uint32_t id)
 211 {
 212         struct mbuf *m, **mnext, *m_frgpart;
 213         struct ip6_hdr *ip6, *mhip6;
 214         struct ip6_frag *ip6f;
 215         int off;
 216         int error;
 217         int tlen = m0->m_pkthdr.len;
 218
 219         KASSERT((fraglen % 8 == 0), ("Fragment length must be a multiple of 8"));
 220
 221         m = m0;
 222         ip6 = mtod(m, struct ip6_hdr *);
 223         mnext = &m->m_nextpkt;
 224
 225         for (off = hlen; off < tlen; off += fraglen) {
 226                 m = m_gethdr(M_NOWAIT, MT_DATA);
 227                 if (!m) {
 228                         IP6STAT_INC(ip6s_odropped);
 229                         return (ENOBUFS);
 230                 }
 231                 m->m_flags = m0->m_flags & M_COPYFLAGS;
 232                 *mnext = m;
 233                 mnext = &m->m_nextpkt;
 234                 m->m_data += max_linkhdr;
 235                 mhip6 = mtod(m, struct ip6_hdr *);
 236                 *mhip6 = *ip6;
 237                 m->m_len = sizeof(*mhip6);
 238                 error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
 239                 if (error) {
 240                         IP6STAT_INC(ip6s_odropped);
 241                         return (error);
 242                 }
 243                 ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
 244                 if (off + fraglen >= tlen)
 245                         fraglen = tlen - off;
 246                 else
 247                         ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
 248                 mhip6->ip6_plen = htons((u_short)(fraglen + hlen +
 249                     sizeof(*ip6f) - sizeof(struct ip6_hdr)));
 250                 if ((m_frgpart = m_copym(m0, off, fraglen, M_NOWAIT)) == NULL) {
 251                         IP6STAT_INC(ip6s_odropped);
 252                         return (ENOBUFS);
 253                 }
 254                 m_cat(m, m_frgpart);
 255                 m->m_pkthdr.len = fraglen + hlen + sizeof(*ip6f);
 256                 m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
 257                 m->m_pkthdr.rcvif = NULL;
 258                 ip6f->ip6f_reserved = 0;
 259                 ip6f->ip6f_ident = id;
 260                 ip6f->ip6f_nxt = nextproto;
 261                 IP6STAT_INC(ip6s_ofragments);
 262                 in6_ifstat_inc(ifp, ifs6_out_fragcreat);
 263         }
 264
 265         return (0);
 266 }
 267
 268 /*
 269  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 270  * header (with pri, len, nxt, hlim, src, dst).
 271  * This function may modify ver and hlim only.
 272  * The mbuf chain containing the packet will be freed.
 273  * The mbuf opt, if present, will not be freed.
 274  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
 275  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
 276  * then result of route lookup is stored in ro->ro_rt.
 277  *
 278  * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
 279  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 280  * which is rt_mtu.
 281  *
 282  * ifpp - XXX: just for statistics
 283  */
 284 /*
 285  * XXX TODO: no flowid is assigned for outbound flows?
 286  */
 287 int
 288 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 289     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 290     struct ifnet **ifpp, struct inpcb *inp)
 291 {
 292         struct ip6_hdr *ip6;
 293         struct ifnet *ifp, *origifp;
 294         struct mbuf *m = m0;
 295         struct mbuf *mprev = NULL;
 296         int hlen, tlen, len;
 297         struct route_in6 ip6route;
 298         struct rtentry *rt = NULL;
 299         struct sockaddr_in6 *dst, src_sa, dst_sa;
 300         struct in6_addr odst;
 301         int error = 0;
 302         struct in6_ifaddr *ia = NULL;
 303         u_long mtu;
 304         int alwaysfrag, dontfrag;
 305         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 306         struct ip6_exthdrs exthdrs;
 307         struct in6_addr src0, dst0;
 308         u_int32_t zone;
 309         struct route_in6 *ro_pmtu = NULL;
 310         int hdrsplit = 0;
 311         int sw_csum, tso;
 312         int needfiblookup;
 313         uint32_t fibnum;
 314         struct m_tag *fwd_tag = NULL;
 315         uint32_t id;
 316
 317         if (inp != NULL) {
 318                 INP_LOCK_ASSERT(inp);
 319                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
 320                 if ((flags & IP_NODEFAULTFLOWID) == 0) {
 321                         /* unconditionally set flowid */
 322                         m->m_pkthdr.flowid = inp->inp_flowid;
 323                         M_HASHTYPE_SET(m, inp->inp_flowtype);
 324                 }
 325         }
 326
 327 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 328         /*
 329          * IPSec checking which handles several cases.
 330          * FAST IPSEC: We re-injected the packet.
 331          * XXX: need scope argument.
 332          */
 333         if (IPSEC_ENABLED(ipv6)) {
 334                 if ((error = IPSEC_OUTPUT(ipv6, m, inp)) != 0) {
 335                         if (error == EINPROGRESS)
 336                                 error = 0;
 337                         goto done;
 338                 }
 339         }
 340 #endif /* IPSEC */
 341
 342         bzero(&exthdrs, sizeof(exthdrs));
 343         if (opt) {
 344                 /* Hop-by-Hop options header */
 345                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 346                 /* Destination options header(1st part) */
 347                 if (opt->ip6po_rthdr) {
 348                         /*
 349                          * Destination options header(1st part)
 350                          * This only makes sense with a routing header.
 351                          * See Section 9.2 of RFC 3542.
 352                          * Disabling this part just for MIP6 convenience is
 353                          * a bad idea.  We need to think carefully about a
 354                          * way to make the advanced API coexist with MIP6
 355                          * options, which might automatically be inserted in
 356                          * the kernel.
 357                          */
 358                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 359                 }
 360                 /* Routing header */
 361                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 362                 /* Destination options header(2nd part) */
 363                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 364         }
 365
 366         /*
 367          * Calculate the total length of the extension header chain.
 368          * Keep the length of the unfragmentable part for fragmentation.
 369          */
 370         optlen = 0;
 371         if (exthdrs.ip6e_hbh)
 372                 optlen += exthdrs.ip6e_hbh->m_len;
 373         if (exthdrs.ip6e_dest1)
 374                 optlen += exthdrs.ip6e_dest1->m_len;
 375         if (exthdrs.ip6e_rthdr)
 376                 optlen += exthdrs.ip6e_rthdr->m_len;
 377         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 378
 379         /* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
 380         if (exthdrs.ip6e_dest2)
 381                 optlen += exthdrs.ip6e_dest2->m_len;
 382
 383         /*
 384          * If there is at least one extension header,
 385          * separate IP6 header from the payload.
 386          */
 387         if (optlen && !hdrsplit) {
 388                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 389                         m = NULL;
 390                         goto freehdrs;
 391                 }
 392                 m = exthdrs.ip6e_ip6;
 393                 hdrsplit++;
 394         }
 395
 396         ip6 = mtod(m, struct ip6_hdr *);
 397
 398         /* adjust mbuf packet header length */
 399         m->m_pkthdr.len += optlen;
 400         plen = m->m_pkthdr.len - sizeof(*ip6);
 401
 402         /* If this is a jumbo payload, insert a jumbo payload option. */
 403         if (plen > IPV6_MAXPACKET) {
 404                 if (!hdrsplit) {
 405                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 406                                 m = NULL;
 407                                 goto freehdrs;
 408                         }
 409                         m = exthdrs.ip6e_ip6;
 410                         hdrsplit++;
 411                 }
 412                 /* adjust pointer */
 413                 ip6 = mtod(m, struct ip6_hdr *);
 414                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 415                         goto freehdrs;
 416                 ip6->ip6_plen = 0;
 417         } else
 418                 ip6->ip6_plen = htons(plen);
 419
 420         /*
 421          * Concatenate headers and fill in next header fields.
 422          * Here we have, on "m"
 423          *      IPv6 payload
 424          * and we insert headers accordingly.  Finally, we should be getting:
 425          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 426          *
 427          * during the header composing process, "m" points to IPv6 header.
 428          * "mprev" points to an extension header prior to esp.
 429          */
 430         u_char *nexthdrp = &ip6->ip6_nxt;
 431         mprev = m;
 432
 433         /*
 434          * we treat dest2 specially.  this makes IPsec processing
 435          * much easier.  the goal here is to make mprev point the
 436          * mbuf prior to dest2.
 437          *
 438          * result: IPv6 dest2 payload
 439          * m and mprev will point to IPv6 header.
 440          */
 441         if (exthdrs.ip6e_dest2) {
 442                 if (!hdrsplit)
 443                         panic("assumption failed: hdr not split");
 444                 exthdrs.ip6e_dest2->m_next = m->m_next;
 445                 m->m_next = exthdrs.ip6e_dest2;
 446                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 447                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 448         }
 449
 450         /*
 451          * result: IPv6 hbh dest1 rthdr dest2 payload
 452          * m will point to IPv6 header.  mprev will point to the
 453          * extension header prior to dest2 (rthdr in the above case).
 454          */
 455         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 456         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 457                    IPPROTO_DSTOPTS);
 458         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 459                    IPPROTO_ROUTING);
 460
 461         /*
 462          * If there is a routing header, discard the packet.
 463          */
 464         if (exthdrs.ip6e_rthdr) {
 465                  error = EINVAL;
 466                  goto bad;
 467         }
 468
 469         /* Source address validation */
 470         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 471             (flags & IPV6_UNSPECSRC) == 0) {
 472                 error = EOPNOTSUPP;
 473                 IP6STAT_INC(ip6s_badscope);
 474                 goto bad;
 475         }
 476         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 477                 error = EOPNOTSUPP;
 478                 IP6STAT_INC(ip6s_badscope);
 479                 goto bad;
 480         }
 481
 482         IP6STAT_INC(ip6s_localout);
 483
 484         /*
 485          * Route packet.
 486          */
 487         if (ro == NULL) {
 488                 ro = &ip6route;
 489                 bzero((caddr_t)ro, sizeof(*ro));
 490         }
 491         ro_pmtu = ro;
 492         if (opt && opt->ip6po_rthdr)
 493                 ro = &opt->ip6po_route;
 494         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 495         fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
 496 again:
 497         /*
 498          * if specified, try to fill in the traffic class field.
 499          * do not override if a non-zero value is already set.
 500          * we check the diffserv field and the ecn field separately.
 501          */
 502         if (opt && opt->ip6po_tclass >= 0) {
 503                 int mask = 0;
 504
 505                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 506                         mask |= 0xfc;
 507                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 508                         mask |= 0x03;
 509                 if (mask != 0)
 510                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 511         }
 512
 513         /* fill in or override the hop limit field, if necessary. */
 514         if (opt && opt->ip6po_hlim != -1)
 515                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 516         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 517                 if (im6o != NULL)
 518                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 519                 else
 520                         ip6->ip6_hlim = V_ip6_defmcasthlim;
 521         }
 522         /*
 523          * Validate route against routing table additions;
 524          * a better/more specific route might have been added.
 525          * Make sure address family is set in route.
 526          */
 527         if (inp) {
 528                 ro->ro_dst.sin6_family = AF_INET6;
 529                 RT_VALIDATE((struct route *)ro, &inp->inp_rt_cookie, fibnum);
 530         }
 531         if (ro->ro_rt && fwd_tag == NULL && (ro->ro_rt->rt_flags & RTF_UP) &&
 532             ro->ro_dst.sin6_family == AF_INET6 &&
 533             IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)) {
 534                 rt = ro->ro_rt;
 535                 ifp = ro->ro_rt->rt_ifp;
 536         } else {
 537                 if (ro->ro_lle)
 538                         LLE_FREE(ro->ro_lle);   /* zeros ro_lle */
 539                 ro->ro_lle = NULL;
 540                 if (fwd_tag == NULL) {
 541                         bzero(&dst_sa, sizeof(dst_sa));
 542                         dst_sa.sin6_family = AF_INET6;
 543                         dst_sa.sin6_len = sizeof(dst_sa);
 544                         dst_sa.sin6_addr = ip6->ip6_dst;
 545                 }
 546                 error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
 547                     &rt, fibnum);
 548                 if (error != 0) {
 549                         if (ifp != NULL)
 550                                 in6_ifstat_inc(ifp, ifs6_out_discard);
 551                         goto bad;
 552                 }
 553         }
 554         if (rt == NULL) {
 555                 /*
 556                  * If in6_selectroute() does not return a route entry,
 557                  * dst may not have been updated.
 558                  */
 559                 *dst = dst_sa;  /* XXX */
 560         }
 561
 562         /*
 563          * then rt (for unicast) and ifp must be non-NULL valid values.
 564          */
 565         if ((flags & IPV6_FORWARDING) == 0) {
 566                 /* XXX: the FORWARDING flag can be set for mrouting. */
 567                 in6_ifstat_inc(ifp, ifs6_out_request);
 568         }
 569         if (rt != NULL) {
 570                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 571                 counter_u64_add(rt->rt_pksent, 1);
 572         }
 573
 574         /* Setup data structures for scope ID checks. */
 575         src0 = ip6->ip6_src;
 576         bzero(&src_sa, sizeof(src_sa));
 577         src_sa.sin6_family = AF_INET6;
 578         src_sa.sin6_len = sizeof(src_sa);
 579         src_sa.sin6_addr = ip6->ip6_src;
 580
 581         dst0 = ip6->ip6_dst;
 582         /* re-initialize to be sure */
 583         bzero(&dst_sa, sizeof(dst_sa));
 584         dst_sa.sin6_family = AF_INET6;
 585         dst_sa.sin6_len = sizeof(dst_sa);
 586         dst_sa.sin6_addr = ip6->ip6_dst;
 587
 588         /* Check for valid scope ID. */
 589         if (in6_setscope(&src0, ifp, &zone) == 0 &&
 590             sa6_recoverscope(&src_sa) == 0 && zone == src_sa.sin6_scope_id &&
 591             in6_setscope(&dst0, ifp, &zone) == 0 &&
 592             sa6_recoverscope(&dst_sa) == 0 && zone == dst_sa.sin6_scope_id) {
 593                 /*
 594                  * The outgoing interface is in the zone of the source
 595                  * and destination addresses.
 596                  *
 597                  * Because the loopback interface cannot receive
 598                  * packets with a different scope ID than its own,
 599                  * there is a trick is to pretend the outgoing packet
 600                  * was received by the real network interface, by
 601                  * setting "origifp" different from "ifp". This is
 602                  * only allowed when "ifp" is a loopback network
 603                  * interface. Refer to code in nd6_output_ifp() for
 604                  * more details.
 605                  */
 606                 origifp = ifp;
 607
 608                 /*
 609                  * We should use ia_ifp to support the case of sending
 610                  * packets to an address of our own.
 611                  */
 612                 if (ia != NULL && ia->ia_ifp)
 613                         ifp = ia->ia_ifp;
 614
 615         } else if ((ifp->if_flags & IFF_LOOPBACK) == 0 ||
 616             sa6_recoverscope(&src_sa) != 0 ||
 617             sa6_recoverscope(&dst_sa) != 0 ||
 618             dst_sa.sin6_scope_id == 0 ||
 619             (src_sa.sin6_scope_id != 0 &&
 620             src_sa.sin6_scope_id != dst_sa.sin6_scope_id) ||
 621             (origifp = ifnet_byindex(dst_sa.sin6_scope_id)) == NULL) {
 622                 /*
 623                  * If the destination network interface is not a
 624                  * loopback interface, or the destination network
 625                  * address has no scope ID, or the source address has
 626                  * a scope ID set which is different from the
 627                  * destination address one, or there is no network
 628                  * interface representing this scope ID, the address
 629                  * pair is considered invalid.
 630                  */
 631                 IP6STAT_INC(ip6s_badscope);
 632                 in6_ifstat_inc(ifp, ifs6_out_discard);
 633                 if (error == 0)
 634                         error = EHOSTUNREACH; /* XXX */
 635                 goto bad;
 636         }
 637
 638         /* All scope ID checks are successful. */
 639
 640         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 641                 if (opt && opt->ip6po_nextroute.ro_rt) {
 642                         /*
 643                          * The nexthop is explicitly specified by the
 644                          * application.  We assume the next hop is an IPv6
 645                          * address.
 646                          */
 647                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 648                 }
 649                 else if ((rt->rt_flags & RTF_GATEWAY))
 650                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 651         }
 652
 653         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 654                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 655         } else {
 656                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 657                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 658                 /*
 659                  * Confirm that the outgoing interface supports multicast.
 660                  */
 661                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 662                         IP6STAT_INC(ip6s_noroute);
 663                         in6_ifstat_inc(ifp, ifs6_out_discard);
 664                         error = ENETUNREACH;
 665                         goto bad;
 666                 }
 667                 if ((im6o == NULL && in6_mcast_loop) ||
 668                     (im6o && im6o->im6o_multicast_loop)) {
 669                         /*
 670                          * Loop back multicast datagram if not expressly
 671                          * forbidden to do so, even if we have not joined
 672                          * the address; protocols will filter it later,
 673                          * thus deferring a hash lookup and lock acquisition
 674                          * at the expense of an m_copym().
 675                          */
 676                         ip6_mloopback(ifp, m);
 677                 } else {
 678                         /*
 679                          * If we are acting as a multicast router, perform
 680                          * multicast forwarding as if the packet had just
 681                          * arrived on the interface to which we are about
 682                          * to send.  The multicast forwarding function
 683                          * recursively calls this function, using the
 684                          * IPV6_FORWARDING flag to prevent infinite recursion.
 685                          *
 686                          * Multicasts that are looped back by ip6_mloopback(),
 687                          * above, will be forwarded by the ip6_input() routine,
 688                          * if necessary.
 689                          */
 690                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 691                                 /*
 692                                  * XXX: ip6_mforward expects that rcvif is NULL
 693                                  * when it is called from the originating path.
 694                                  * However, it may not always be the case.
 695                                  */
 696                                 m->m_pkthdr.rcvif = NULL;
 697                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 698                                         m_freem(m);
 699                                         goto done;
 700                                 }
 701                         }
 702                 }
 703                 /*
 704                  * Multicasts with a hoplimit of zero may be looped back,
 705                  * above, but must not be transmitted on a network.
 706                  * Also, multicasts addressed to the loopback interface
 707                  * are not sent -- the above call to ip6_mloopback() will
 708                  * loop back a copy if this host actually belongs to the
 709                  * destination group on the loopback interface.
 710                  */
 711                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 712                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 713                         m_freem(m);
 714                         goto done;
 715                 }
 716         }
 717
 718         /*
 719          * Fill the outgoing inteface to tell the upper layer
 720          * to increment per-interface statistics.
 721          */
 722         if (ifpp)
 723                 *ifpp = ifp;
 724
 725         /* Determine path MTU. */
 726         if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &ip6->ip6_dst,
 727                     &mtu, &alwaysfrag, fibnum, *nexthdrp)) != 0)
 728                 goto bad;
 729
 730         /*
 731          * The caller of this function may specify to use the minimum MTU
 732          * in some cases.
 733          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 734          * setting.  The logic is a bit complicated; by default, unicast
 735          * packets will follow path MTU while multicast packets will be sent at
 736          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 737          * including unicast ones will be sent at the minimum MTU.  Multicast
 738          * packets will always be sent at the minimum MTU unless
 739          * IP6PO_MINMTU_DISABLE is explicitly specified.
 740          * See RFC 3542 for more details.
 741          */
 742         if (mtu > IPV6_MMTU) {
 743                 if ((flags & IPV6_MINMTU))
 744                         mtu = IPV6_MMTU;
 745                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 746                         mtu = IPV6_MMTU;
 747                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 748                          (opt == NULL ||
 749                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 750                         mtu = IPV6_MMTU;
 751                 }
 752         }
 753
 754         /*
 755          * clear embedded scope identifiers if necessary.
 756          * in6_clearscope will touch the addresses only when necessary.
 757          */
 758         in6_clearscope(&ip6->ip6_src);
 759         in6_clearscope(&ip6->ip6_dst);
 760
 761         /*
 762          * If the outgoing packet contains a hop-by-hop options header,
 763          * it must be examined and processed even by the source node.
 764          * (RFC 2460, section 4.)
 765          */
 766         if (exthdrs.ip6e_hbh) {
 767                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 768                 u_int32_t dummy; /* XXX unused */
 769                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 770
 771 #ifdef DIAGNOSTIC
 772                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 773                         panic("ip6e_hbh is not contiguous");
 774 #endif
 775                 /*
 776                  *  XXX: if we have to send an ICMPv6 error to the sender,
 777                  *       we need the M_LOOP flag since icmp6_error() expects
 778                  *       the IPv6 and the hop-by-hop options header are
 779                  *       contiguous unless the flag is set.
 780                  */
 781                 m->m_flags |= M_LOOP;
 782                 m->m_pkthdr.rcvif = ifp;
 783                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 784                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 785                     &dummy, &plen) < 0) {
 786                         /* m was already freed at this point */
 787                         error = EINVAL;/* better error? */
 788                         goto done;
 789                 }
 790                 m->m_flags &= ~M_LOOP; /* XXX */
 791                 m->m_pkthdr.rcvif = NULL;
 792         }
 793
 794         /* Jump over all PFIL processing if hooks are not active. */
 795         if (!PFIL_HOOKED_OUT(V_inet6_pfil_head))
 796                 goto passout;
 797
 798         odst = ip6->ip6_dst;
 799         /* Run through list of hooks for output packets. */
 800         switch (pfil_run_hooks(V_inet6_pfil_head, &m, ifp, PFIL_OUT, inp)) {
 801         case PFIL_PASS:
 802                 ip6 = mtod(m, struct ip6_hdr *);
 803                 break;
 804         case PFIL_DROPPED:
 805                 error = EPERM;
 806                 /* FALLTHROUGH */
 807         case PFIL_CONSUMED:
 808                 goto done;
 809         }
 810
 811         needfiblookup = 0;
 812         /* See if destination IP address was changed by packet filter. */
 813         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 814                 m->m_flags |= M_SKIP_FIREWALL;
 815                 /* If destination is now ourself drop to ip6_input(). */
 816                 if (in6_localip(&ip6->ip6_dst)) {
 817                         m->m_flags |= M_FASTFWD_OURS;
 818                         if (m->m_pkthdr.rcvif == NULL)
 819                                 m->m_pkthdr.rcvif = V_loif;
 820                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 821                                 m->m_pkthdr.csum_flags |=
 822                                     CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 823                                 m->m_pkthdr.csum_data = 0xffff;
 824                         }
 825 #ifdef SCTP
 826                         if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 827                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 828 #endif
 829                         error = netisr_queue(NETISR_IPV6, m);
 830                         goto done;
 831                 } else {
 832                         RO_INVALIDATE_CACHE(ro);
 833                         needfiblookup = 1; /* Redo the routing table lookup. */
 834                 }
 835         }
 836         /* See if fib was changed by packet filter. */
 837         if (fibnum != M_GETFIB(m)) {
 838                 m->m_flags |= M_SKIP_FIREWALL;
 839                 fibnum = M_GETFIB(m);
 840                 RO_INVALIDATE_CACHE(ro);
 841                 needfiblookup = 1;
 842         }
 843         if (needfiblookup)
 844                 goto again;
 845
 846         /* See if local, if yes, send it to netisr. */
 847         if (m->m_flags & M_FASTFWD_OURS) {
 848                 if (m->m_pkthdr.rcvif == NULL)
 849                         m->m_pkthdr.rcvif = V_loif;
 850                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 851                         m->m_pkthdr.csum_flags |=
 852                             CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 853                         m->m_pkthdr.csum_data = 0xffff;
 854                 }
 855 #ifdef SCTP
 856                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 857                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 858 #endif
 859                 error = netisr_queue(NETISR_IPV6, m);
 860                 goto done;
 861         }
 862         /* Or forward to some other address? */
 863         if ((m->m_flags & M_IP6_NEXTHOP) &&
 864             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 865                 dst = (struct sockaddr_in6 *)&ro->ro_dst;
 866                 bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
 867                 m->m_flags |= M_SKIP_FIREWALL;
 868                 m->m_flags &= ~M_IP6_NEXTHOP;
 869                 m_tag_delete(m, fwd_tag);
 870                 goto again;
 871         }
 872
 873 passout:
 874         /*
 875          * Send the packet to the outgoing interface.
 876          * If necessary, do IPv6 fragmentation before sending.
 877          *
 878          * the logic here is rather complex:
 879          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 880          * 1-a: send as is if tlen <= path mtu
 881          * 1-b: fragment if tlen > path mtu
 882          *
 883          * 2: if user asks us not to fragment (dontfrag == 1)
 884          * 2-a: send as is if tlen <= interface mtu
 885          * 2-b: error if tlen > interface mtu
 886          *
 887          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 888          *      always fragment
 889          *
 890          * 4: if dontfrag == 1 && alwaysfrag == 1
 891          *      error, as we cannot handle this conflicting request
 892          */
 893         sw_csum = m->m_pkthdr.csum_flags;
 894         if (!hdrsplit) {
 895                 tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
 896                 sw_csum &= ~ifp->if_hwassist;
 897         } else
 898                 tso = 0;
 899         /*
 900          * If we added extension headers, we will not do TSO and calculate the
 901          * checksums ourselves for now.
 902          * XXX-BZ  Need a framework to know when the NIC can handle it, even
 903          * with ext. hdrs.
 904          */
 905         if (sw_csum & CSUM_DELAY_DATA_IPV6) {
 906                 sw_csum &= ~CSUM_DELAY_DATA_IPV6;
 907                 in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
 908         }
 909 #ifdef SCTP
 910         if (sw_csum & CSUM_SCTP_IPV6) {
 911                 sw_csum &= ~CSUM_SCTP_IPV6;
 912                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 913         }
 914 #endif
 915         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
 916         tlen = m->m_pkthdr.len;
 917
 918         if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
 919                 dontfrag = 1;
 920         else
 921                 dontfrag = 0;
 922         if (dontfrag && alwaysfrag) {   /* case 4 */
 923                 /* conflicting request - can't transmit */
 924                 error = EMSGSIZE;
 925                 goto bad;
 926         }
 927         if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {      /* case 2-b */
 928                 /*
 929                  * Even if the DONTFRAG option is specified, we cannot send the
 930                  * packet when the data length is larger than the MTU of the
 931                  * outgoing interface.
 932                  * Notify the error by sending IPV6_PATHMTU ancillary data if
 933                  * application wanted to know the MTU value. Also return an
 934                  * error code (this is not described in the API spec).
 935                  */
 936                 if (inp != NULL)
 937                         ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
 938                 error = EMSGSIZE;
 939                 goto bad;
 940         }
 941
 942         /*
 943          * transmit packet without fragmentation
 944          */
 945         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 946                 struct in6_ifaddr *ia6;
 947
 948                 ip6 = mtod(m, struct ip6_hdr *);
 949                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 950                 if (ia6) {
 951                         /* Record statistics for this interface address. */
 952                         counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
 953                         counter_u64_add(ia6->ia_ifa.ifa_obytes,
 954                             m->m_pkthdr.len);
 955                         ifa_free(&ia6->ia_ifa);
 956                 }
 957 #ifdef RATELIMIT
 958                 if (inp != NULL) {
 959                         if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
 960                                 in_pcboutput_txrtlmt(inp, ifp, m);
 961                         /* stamp send tag on mbuf */
 962                         m->m_pkthdr.snd_tag = inp->inp_snd_tag;
 963                 } else {
 964                         m->m_pkthdr.snd_tag = NULL;
 965                 }
 966 #endif
 967                 error = nd6_output_ifp(ifp, origifp, m, dst,
 968                     (struct route *)ro);
 969 #ifdef RATELIMIT
 970                 /* check for route change */
 971                 if (error == EAGAIN)
 972                         in_pcboutput_eagain(inp);
 973 #endif
 974                 goto done;
 975         }
 976
 977         /*
 978          * try to fragment the packet.  case 1-b and 3
 979          */
 980         if (mtu < IPV6_MMTU) {
 981                 /* path MTU cannot be less than IPV6_MMTU */
 982                 error = EMSGSIZE;
 983                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 984                 goto bad;
 985         } else if (ip6->ip6_plen == 0) {
 986                 /* jumbo payload cannot be fragmented */
 987                 error = EMSGSIZE;
 988                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 989                 goto bad;
 990         } else {
 991                 u_char nextproto;
 992
 993                 /*
 994                  * Too large for the destination or interface;
 995                  * fragment if possible.
 996                  * Must be able to put at least 8 bytes per fragment.
 997                  */
 998                 hlen = unfragpartlen;
 999                 if (mtu > IPV6_MAXPACKET)
1000                         mtu = IPV6_MAXPACKET;
1001
1002                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
1003                 if (len < 8) {
1004                         error = EMSGSIZE;
1005                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
1006                         goto bad;
1007                 }
1008
1009                 /*
1010                  * If the interface will not calculate checksums on
1011                  * fragmented packets, then do it here.
1012                  * XXX-BZ handle the hw offloading case.  Need flags.
1013                  */
1014                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1015                         in6_delayed_cksum(m, plen, hlen);
1016                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
1017                 }
1018 #ifdef SCTP
1019                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
1020                         sctp_delayed_cksum(m, hlen);
1021                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
1022                 }
1023 #endif
1024                 /*
1025                  * Change the next header field of the last header in the
1026                  * unfragmentable part.
1027                  */
1028                 if (exthdrs.ip6e_rthdr) {
1029                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1030                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1031                 } else if (exthdrs.ip6e_dest1) {
1032                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1033                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1034                 } else if (exthdrs.ip6e_hbh) {
1035                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1036                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1037                 } else {
1038                         nextproto = ip6->ip6_nxt;
1039                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
1040                 }
1041
1042                 /*
1043                  * Loop through length of segment after first fragment,
1044                  * make new header and copy data of each part and link onto
1045                  * chain.
1046                  */
1047                 m0 = m;
1048                 id = htonl(ip6_randomid());
1049                 if ((error = ip6_fragment(ifp, m, hlen, nextproto, len, id)))
1050                         goto sendorfree;
1051
1052                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1053         }
1054
1055         /*
1056          * Remove leading garbages.
1057          */
1058 sendorfree:
1059         m = m0->m_nextpkt;
1060         m0->m_nextpkt = 0;
1061         m_freem(m0);
1062         for (; m; m = m0) {
1063                 m0 = m->m_nextpkt;
1064                 m->m_nextpkt = 0;
1065                 if (error == 0) {
1066                         /* Record statistics for this interface address. */
1067                         if (ia) {
1068                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1069                                 counter_u64_add(ia->ia_ifa.ifa_obytes,
1070                                     m->m_pkthdr.len);
1071                         }
1072 #ifdef RATELIMIT
1073                         if (inp != NULL) {
1074                                 if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
1075                                         in_pcboutput_txrtlmt(inp, ifp, m);
1076                                 /* stamp send tag on mbuf */
1077                                 m->m_pkthdr.snd_tag = inp->inp_snd_tag;
1078                         } else {
1079                                 m->m_pkthdr.snd_tag = NULL;
1080                         }
1081 #endif
1082                         error = nd6_output_ifp(ifp, origifp, m, dst,
1083                             (struct route *)ro);
1084 #ifdef RATELIMIT
1085                         /* check for route change */
1086                         if (error == EAGAIN)
1087                                 in_pcboutput_eagain(inp);
1088 #endif
1089                 } else
1090                         m_freem(m);
1091         }
1092
1093         if (error == 0)
1094                 IP6STAT_INC(ip6s_fragmented);
1095
1096 done:
1097         if (ro == &ip6route)
1098                 RO_RTFREE(ro);
1099         return (error);
1100
1101 freehdrs:
1102         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1103         m_freem(exthdrs.ip6e_dest1);
1104         m_freem(exthdrs.ip6e_rthdr);
1105         m_freem(exthdrs.ip6e_dest2);
1106         /* FALLTHROUGH */
1107 bad:
1108         if (m)
1109                 m_freem(m);
1110         goto done;
1111 }
1112
1113 static int
1114 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1115 {
1116         struct mbuf *m;
1117
1118         if (hlen > MCLBYTES)
1119                 return (ENOBUFS); /* XXX */
1120
1121         if (hlen > MLEN)
1122                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1123         else
1124                 m = m_get(M_NOWAIT, MT_DATA);
1125         if (m == NULL)
1126                 return (ENOBUFS);
1127         m->m_len = hlen;
1128         if (hdr)
1129                 bcopy(hdr, mtod(m, caddr_t), hlen);
1130
1131         *mp = m;
1132         return (0);
1133 }
1134
1135 /*
1136  * Insert jumbo payload option.
1137  */
1138 static int
1139 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1140 {
1141         struct mbuf *mopt;
1142         u_char *optbuf;
1143         u_int32_t v;
1144
1145 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1146
1147         /*
1148          * If there is no hop-by-hop options header, allocate new one.
1149          * If there is one but it doesn't have enough space to store the
1150          * jumbo payload option, allocate a cluster to store the whole options.
1151          * Otherwise, use it to store the options.
1152          */
1153         if (exthdrs->ip6e_hbh == NULL) {
1154                 mopt = m_get(M_NOWAIT, MT_DATA);
1155                 if (mopt == NULL)
1156                         return (ENOBUFS);
1157                 mopt->m_len = JUMBOOPTLEN;
1158                 optbuf = mtod(mopt, u_char *);
1159                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1160                 exthdrs->ip6e_hbh = mopt;
1161         } else {
1162                 struct ip6_hbh *hbh;
1163
1164                 mopt = exthdrs->ip6e_hbh;
1165                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1166                         /*
1167                          * XXX assumption:
1168                          * - exthdrs->ip6e_hbh is not referenced from places
1169                          *   other than exthdrs.
1170                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1171                          */
1172                         int oldoptlen = mopt->m_len;
1173                         struct mbuf *n;
1174
1175                         /*
1176                          * XXX: give up if the whole (new) hbh header does
1177                          * not fit even in an mbuf cluster.
1178                          */
1179                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1180                                 return (ENOBUFS);
1181
1182                         /*
1183                          * As a consequence, we must always prepare a cluster
1184                          * at this point.
1185                          */
1186                         n = m_getcl(M_NOWAIT, MT_DATA, 0);
1187                         if (n == NULL)
1188                                 return (ENOBUFS);
1189                         n->m_len = oldoptlen + JUMBOOPTLEN;
1190                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1191                             oldoptlen);
1192                         optbuf = mtod(n, caddr_t) + oldoptlen;
1193                         m_freem(mopt);
1194                         mopt = exthdrs->ip6e_hbh = n;
1195                 } else {
1196                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1197                         mopt->m_len += JUMBOOPTLEN;
1198                 }
1199                 optbuf[0] = IP6OPT_PADN;
1200                 optbuf[1] = 1;
1201
1202                 /*
1203                  * Adjust the header length according to the pad and
1204                  * the jumbo payload option.
1205                  */
1206                 hbh = mtod(mopt, struct ip6_hbh *);
1207                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1208         }
1209
1210         /* fill in the option. */
1211         optbuf[2] = IP6OPT_JUMBO;
1212         optbuf[3] = 4;
1213         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1214         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1215
1216         /* finally, adjust the packet header length */
1217         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1218
1219         return (0);
1220 #undef JUMBOOPTLEN
1221 }
1222
1223 /*
1224  * Insert fragment header and copy unfragmentable header portions.
1225  */
1226 static int
1227 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1228     struct ip6_frag **frghdrp)
1229 {
1230         struct mbuf *n, *mlast;
1231
1232         if (hlen > sizeof(struct ip6_hdr)) {
1233                 n = m_copym(m0, sizeof(struct ip6_hdr),
1234                     hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1235                 if (n == NULL)
1236                         return (ENOBUFS);
1237                 m->m_next = n;
1238         } else
1239                 n = m;
1240
1241         /* Search for the last mbuf of unfragmentable part. */
1242         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1243                 ;
1244
1245         if (M_WRITABLE(mlast) &&
1246             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1247                 /* use the trailing space of the last mbuf for the fragment hdr */
1248                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1249                     mlast->m_len);
1250                 mlast->m_len += sizeof(struct ip6_frag);
1251                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1252         } else {
1253                 /* allocate a new mbuf for the fragment header */
1254                 struct mbuf *mfrg;
1255
1256                 mfrg = m_get(M_NOWAIT, MT_DATA);
1257                 if (mfrg == NULL)
1258                         return (ENOBUFS);
1259                 mfrg->m_len = sizeof(struct ip6_frag);
1260                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1261                 mlast->m_next = mfrg;
1262         }
1263
1264         return (0);
1265 }
1266
1267 /*
1268  * Calculates IPv6 path mtu for destination @dst.
1269  * Resulting MTU is stored in @mtup.
1270  *
1271  * Returns 0 on success.
1272  */
1273 static int
1274 ip6_getpmtu_ctl(u_int fibnum, const struct in6_addr *dst, u_long *mtup)
1275 {
1276         struct nhop6_extended nh6;
1277         struct in6_addr kdst;
1278         uint32_t scopeid;
1279         struct ifnet *ifp;
1280         u_long mtu;
1281         int error;
1282
1283         in6_splitscope(dst, &kdst, &scopeid);
1284         if (fib6_lookup_nh_ext(fibnum, &kdst, scopeid, NHR_REF, 0, &nh6) != 0)
1285                 return (EHOSTUNREACH);
1286
1287         ifp = nh6.nh_ifp;
1288         mtu = nh6.nh_mtu;
1289
1290         error = ip6_calcmtu(ifp, dst, mtu, mtup, NULL, 0);
1291         fib6_free_nh_ext(fibnum, &nh6);
1292
1293         return (error);
1294 }
1295
1296 /*
1297  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1298  * and cached data in @ro_pmtu.
1299  * MTU from (successful) route lookup is saved (along with dst)
1300  * inside @ro_pmtu to avoid subsequent route lookups after packet
1301  * filter processing.
1302  *
1303  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1304  * Returns 0 on success.
1305  */
1306 static int
1307 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1308     struct ifnet *ifp, const struct in6_addr *dst, u_long *mtup,
1309     int *alwaysfragp, u_int fibnum, u_int proto)
1310 {
1311         struct nhop6_basic nh6;
1312         struct in6_addr kdst;
1313         uint32_t scopeid;
1314         struct sockaddr_in6 *sa6_dst;
1315         u_long mtu;
1316
1317         mtu = 0;
1318         if (do_lookup) {
1319
1320                 /*
1321                  * Here ro_pmtu has final destination address, while
1322                  * ro might represent immediate destination.
1323                  * Use ro_pmtu destination since mtu might differ.
1324                  */
1325                 sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1326                 if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1327                         ro_pmtu->ro_mtu = 0;
1328
1329                 if (ro_pmtu->ro_mtu == 0) {
1330                         bzero(sa6_dst, sizeof(*sa6_dst));
1331                         sa6_dst->sin6_family = AF_INET6;
1332                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1333                         sa6_dst->sin6_addr = *dst;
1334
1335                         in6_splitscope(dst, &kdst, &scopeid);
1336                         if (fib6_lookup_nh_basic(fibnum, &kdst, scopeid, 0, 0,
1337                             &nh6) == 0)
1338                                 ro_pmtu->ro_mtu = nh6.nh_mtu;
1339                 }
1340
1341                 mtu = ro_pmtu->ro_mtu;
1342         }
1343
1344         if (ro_pmtu->ro_rt)
1345                 mtu = ro_pmtu->ro_rt->rt_mtu;
1346
1347         return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp, proto));
1348 }
1349
1350 /*
1351  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1352  * hostcache data for @dst.
1353  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1354  *
1355  * Returns 0 on success.
1356  */
1357 static int
1358 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1359     u_long *mtup, int *alwaysfragp, u_int proto)
1360 {
1361         u_long mtu = 0;
1362         int alwaysfrag = 0;
1363         int error = 0;
1364
1365         if (rt_mtu > 0) {
1366                 u_int32_t ifmtu;
1367                 struct in_conninfo inc;
1368
1369                 bzero(&inc, sizeof(inc));
1370                 inc.inc_flags |= INC_ISIPV6;
1371                 inc.inc6_faddr = *dst;
1372
1373                 ifmtu = IN6_LINKMTU(ifp);
1374
1375                 /* TCP is known to react to pmtu changes so skip hc */
1376                 if (proto != IPPROTO_TCP)
1377                         mtu = tcp_hc_getmtu(&inc);
1378
1379                 if (mtu)
1380                         mtu = min(mtu, rt_mtu);
1381                 else
1382                         mtu = rt_mtu;
1383                 if (mtu == 0)
1384                         mtu = ifmtu;
1385                 else if (mtu < IPV6_MMTU) {
1386                         /*
1387                          * RFC2460 section 5, last paragraph:
1388                          * if we record ICMPv6 too big message with
1389                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1390                          * or smaller, with framgent header attached.
1391                          * (fragment header is needed regardless from the
1392                          * packet size, for translators to identify packets)
1393                          */
1394                         alwaysfrag = 1;
1395                         mtu = IPV6_MMTU;
1396                 }
1397         } else if (ifp) {
1398                 mtu = IN6_LINKMTU(ifp);
1399         } else
1400                 error = EHOSTUNREACH; /* XXX */
1401
1402         *mtup = mtu;
1403         if (alwaysfragp)
1404                 *alwaysfragp = alwaysfrag;
1405         return (error);
1406 }
1407
1408 /*
1409  * IP6 socket option processing.
1410  */
1411 int
1412 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1413 {
1414         int optdatalen, uproto;
1415         void *optdata;
1416         struct inpcb *in6p = sotoinpcb(so);
1417         int error, optval;
1418         int level, op, optname;
1419         int optlen;
1420         struct thread *td;
1421 #ifdef  RSS
1422         uint32_t rss_bucket;
1423         int retval;
1424 #endif
1425
1426 /*
1427  * Don't use more than a quarter of mbuf clusters.  N.B.:
1428  * nmbclusters is an int, but nmbclusters * MCLBYTES may overflow
1429  * on LP64 architectures, so cast to u_long to avoid undefined
1430  * behavior.  ILP32 architectures cannot have nmbclusters
1431  * large enough to overflow for other reasons.
1432  */
1433 #define IPV6_PKTOPTIONS_MBUF_LIMIT      ((u_long)nmbclusters * MCLBYTES / 4)
1434
1435         level = sopt->sopt_level;
1436         op = sopt->sopt_dir;
1437         optname = sopt->sopt_name;
1438         optlen = sopt->sopt_valsize;
1439         td = sopt->sopt_td;
1440         error = 0;
1441         optval = 0;
1442         uproto = (int)so->so_proto->pr_protocol;
1443
1444         if (level != IPPROTO_IPV6) {
1445                 error = EINVAL;
1446
1447                 if (sopt->sopt_level == SOL_SOCKET &&
1448                     sopt->sopt_dir == SOPT_SET) {
1449                         switch (sopt->sopt_name) {
1450                         case SO_REUSEADDR:
1451                                 INP_WLOCK(in6p);
1452                                 if ((so->so_options & SO_REUSEADDR) != 0)
1453                                         in6p->inp_flags2 |= INP_REUSEADDR;
1454                                 else
1455                                         in6p->inp_flags2 &= ~INP_REUSEADDR;
1456                                 INP_WUNLOCK(in6p);
1457                                 error = 0;
1458                                 break;
1459                         case SO_REUSEPORT:
1460                                 INP_WLOCK(in6p);
1461                                 if ((so->so_options & SO_REUSEPORT) != 0)
1462                                         in6p->inp_flags2 |= INP_REUSEPORT;
1463                                 else
1464                                         in6p->inp_flags2 &= ~INP_REUSEPORT;
1465                                 INP_WUNLOCK(in6p);
1466                                 error = 0;
1467                                 break;
1468                         case SO_REUSEPORT_LB:
1469                                 INP_WLOCK(in6p);
1470                                 if ((so->so_options & SO_REUSEPORT_LB) != 0)
1471                                         in6p->inp_flags2 |= INP_REUSEPORT_LB;
1472                                 else
1473                                         in6p->inp_flags2 &= ~INP_REUSEPORT_LB;
1474                                 INP_WUNLOCK(in6p);
1475                                 error = 0;
1476                                 break;
1477                         case SO_SETFIB:
1478                                 INP_WLOCK(in6p);
1479                                 in6p->inp_inc.inc_fibnum = so->so_fibnum;
1480                                 INP_WUNLOCK(in6p);
1481                                 error = 0;
1482                                 break;
1483                         case SO_MAX_PACING_RATE:
1484 #ifdef RATELIMIT
1485                                 INP_WLOCK(in6p);
1486                                 in6p->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1487                                 INP_WUNLOCK(in6p);
1488                                 error = 0;
1489 #else
1490                                 error = EOPNOTSUPP;
1491 #endif
1492                                 break;
1493                         default:
1494                                 break;
1495                         }
1496                 }
1497         } else {                /* level == IPPROTO_IPV6 */
1498                 switch (op) {
1499
1500                 case SOPT_SET:
1501                         switch (optname) {
1502                         case IPV6_2292PKTOPTIONS:
1503 #ifdef IPV6_PKTOPTIONS
1504                         case IPV6_PKTOPTIONS:
1505 #endif
1506                         {
1507                                 struct mbuf *m;
1508
1509                                 if (optlen > IPV6_PKTOPTIONS_MBUF_LIMIT) {
1510                                         printf("ip6_ctloutput: mbuf limit hit\n");
1511                                         error = ENOBUFS;
1512                                         break;
1513                                 }
1514
1515                                 error = soopt_getm(sopt, &m); /* XXX */
1516                                 if (error != 0)
1517                                         break;
1518                                 error = soopt_mcopyin(sopt, m); /* XXX */
1519                                 if (error != 0)
1520                                         break;
1521                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1522                                                     m, so, sopt);
1523                                 m_freem(m); /* XXX */
1524                                 break;
1525                         }
1526
1527                         /*
1528                          * Use of some Hop-by-Hop options or some
1529                          * Destination options, might require special
1530                          * privilege.  That is, normal applications
1531                          * (without special privilege) might be forbidden
1532                          * from setting certain options in outgoing packets,
1533                          * and might never see certain options in received
1534                          * packets. [RFC 2292 Section 6]
1535                          * KAME specific note:
1536                          *  KAME prevents non-privileged users from sending or
1537                          *  receiving ANY hbh/dst options in order to avoid
1538                          *  overhead of parsing options in the kernel.
1539                          */
1540                         case IPV6_RECVHOPOPTS:
1541                         case IPV6_RECVDSTOPTS:
1542                         case IPV6_RECVRTHDRDSTOPTS:
1543                                 if (td != NULL) {
1544                                         error = priv_check(td,
1545                                             PRIV_NETINET_SETHDROPTS);
1546                                         if (error)
1547                                                 break;
1548                                 }
1549                                 /* FALLTHROUGH */
1550                         case IPV6_UNICAST_HOPS:
1551                         case IPV6_HOPLIMIT:
1552
1553                         case IPV6_RECVPKTINFO:
1554                         case IPV6_RECVHOPLIMIT:
1555                         case IPV6_RECVRTHDR:
1556                         case IPV6_RECVPATHMTU:
1557                         case IPV6_RECVTCLASS:
1558                         case IPV6_RECVFLOWID:
1559 #ifdef  RSS
1560                         case IPV6_RECVRSSBUCKETID:
1561 #endif
1562                         case IPV6_V6ONLY:
1563                         case IPV6_AUTOFLOWLABEL:
1564                         case IPV6_ORIGDSTADDR:
1565                         case IPV6_BINDANY:
1566                         case IPV6_BINDMULTI:
1567 #ifdef  RSS
1568                         case IPV6_RSS_LISTEN_BUCKET:
1569 #endif
1570                                 if (optname == IPV6_BINDANY && td != NULL) {
1571                                         error = priv_check(td,
1572                                             PRIV_NETINET_BINDANY);
1573                                         if (error)
1574                                                 break;
1575                                 }
1576
1577                                 if (optlen != sizeof(int)) {
1578                                         error = EINVAL;
1579                                         break;
1580                                 }
1581                                 error = sooptcopyin(sopt, &optval,
1582                                         sizeof optval, sizeof optval);
1583                                 if (error)
1584                                         break;
1585                                 switch (optname) {
1586
1587                                 case IPV6_UNICAST_HOPS:
1588                                         if (optval < -1 || optval >= 256)
1589                                                 error = EINVAL;
1590                                         else {
1591                                                 /* -1 = kernel default */
1592                                                 in6p->in6p_hops = optval;
1593                                                 if ((in6p->inp_vflag &
1594                                                      INP_IPV4) != 0)
1595                                                         in6p->inp_ip_ttl = optval;
1596                                         }
1597                                         break;
1598 #define OPTSET(bit) \
1599 do { \
1600         INP_WLOCK(in6p); \
1601         if (optval) \
1602                 in6p->inp_flags |= (bit); \
1603         else \
1604                 in6p->inp_flags &= ~(bit); \
1605         INP_WUNLOCK(in6p); \
1606 } while (/*CONSTCOND*/ 0)
1607 #define OPTSET2292(bit) \
1608 do { \
1609         INP_WLOCK(in6p); \
1610         in6p->inp_flags |= IN6P_RFC2292; \
1611         if (optval) \
1612                 in6p->inp_flags |= (bit); \
1613         else \
1614                 in6p->inp_flags &= ~(bit); \
1615         INP_WUNLOCK(in6p); \
1616 } while (/*CONSTCOND*/ 0)
1617 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1618
1619 #define OPTSET2_N(bit, val) do {                                        \
1620         if (val)                                                        \
1621                 in6p->inp_flags2 |= bit;                                \
1622         else                                                            \
1623                 in6p->inp_flags2 &= ~bit;                               \
1624 } while (0)
1625 #define OPTSET2(bit, val) do {                                          \
1626         INP_WLOCK(in6p);                                                \
1627         OPTSET2_N(bit, val);                                            \
1628         INP_WUNLOCK(in6p);                                              \
1629 } while (0)
1630 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1631 #define OPTSET2292_EXCLUSIVE(bit)                                       \
1632 do {                                                                    \
1633         INP_WLOCK(in6p);                                                \
1634         if (OPTBIT(IN6P_RFC2292)) {                                     \
1635                 error = EINVAL;                                         \
1636         } else {                                                        \
1637                 if (optval)                                             \
1638                         in6p->inp_flags |= (bit);                       \
1639                 else                                                    \
1640                         in6p->inp_flags &= ~(bit);                      \
1641         }                                                               \
1642         INP_WUNLOCK(in6p);                                              \
1643 } while (/*CONSTCOND*/ 0)
1644
1645                                 case IPV6_RECVPKTINFO:
1646                                         OPTSET2292_EXCLUSIVE(IN6P_PKTINFO);
1647                                         break;
1648
1649                                 case IPV6_HOPLIMIT:
1650                                 {
1651                                         struct ip6_pktopts **optp;
1652
1653                                         /* cannot mix with RFC2292 */
1654                                         if (OPTBIT(IN6P_RFC2292)) {
1655                                                 error = EINVAL;
1656                                                 break;
1657                                         }
1658                                         INP_WLOCK(in6p);
1659                                         if (in6p->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1660                                                 INP_WUNLOCK(in6p);
1661                                                 return (ECONNRESET);
1662                                         }
1663                                         optp = &in6p->in6p_outputopts;
1664                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1665                                             (u_char *)&optval, sizeof(optval),
1666                                             optp, (td != NULL) ? td->td_ucred :
1667                                             NULL, uproto);
1668                                         INP_WUNLOCK(in6p);
1669                                         break;
1670                                 }
1671
1672                                 case IPV6_RECVHOPLIMIT:
1673                                         OPTSET2292_EXCLUSIVE(IN6P_HOPLIMIT);
1674                                         break;
1675
1676                                 case IPV6_RECVHOPOPTS:
1677                                         OPTSET2292_EXCLUSIVE(IN6P_HOPOPTS);
1678                                         break;
1679
1680                                 case IPV6_RECVDSTOPTS:
1681                                         OPTSET2292_EXCLUSIVE(IN6P_DSTOPTS);
1682                                         break;
1683
1684                                 case IPV6_RECVRTHDRDSTOPTS:
1685                                         OPTSET2292_EXCLUSIVE(IN6P_RTHDRDSTOPTS);
1686                                         break;
1687
1688                                 case IPV6_RECVRTHDR:
1689                                         OPTSET2292_EXCLUSIVE(IN6P_RTHDR);
1690                                         break;
1691
1692                                 case IPV6_RECVPATHMTU:
1693                                         /*
1694                                          * We ignore this option for TCP
1695                                          * sockets.
1696                                          * (RFC3542 leaves this case
1697                                          * unspecified.)
1698                                          */
1699                                         if (uproto != IPPROTO_TCP)
1700                                                 OPTSET(IN6P_MTU);
1701                                         break;
1702
1703                                 case IPV6_RECVFLOWID:
1704                                         OPTSET2(INP_RECVFLOWID, optval);
1705                                         break;
1706
1707 #ifdef  RSS
1708                                 case IPV6_RECVRSSBUCKETID:
1709                                         OPTSET2(INP_RECVRSSBUCKETID, optval);
1710                                         break;
1711 #endif
1712
1713                                 case IPV6_V6ONLY:
1714                                         /*
1715                                          * make setsockopt(IPV6_V6ONLY)
1716                                          * available only prior to bind(2).
1717                                          * see ipng mailing list, Jun 22 2001.
1718                                          */
1719                                         if (in6p->inp_lport ||
1720                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1721                                                 error = EINVAL;
1722                                                 break;
1723                                         }
1724                                         OPTSET(IN6P_IPV6_V6ONLY);
1725                                         if (optval)
1726                                                 in6p->inp_vflag &= ~INP_IPV4;
1727                                         else
1728                                                 in6p->inp_vflag |= INP_IPV4;
1729                                         break;
1730                                 case IPV6_RECVTCLASS:
1731                                         /* cannot mix with RFC2292 XXX */
1732                                         OPTSET2292_EXCLUSIVE(IN6P_TCLASS);
1733                                         break;
1734                                 case IPV6_AUTOFLOWLABEL:
1735                                         OPTSET(IN6P_AUTOFLOWLABEL);
1736                                         break;
1737
1738                                 case IPV6_ORIGDSTADDR:
1739                                         OPTSET2(INP_ORIGDSTADDR, optval);
1740                                         break;
1741                                 case IPV6_BINDANY:
1742                                         OPTSET(INP_BINDANY);
1743                                         break;
1744
1745                                 case IPV6_BINDMULTI:
1746                                         OPTSET2(INP_BINDMULTI, optval);
1747                                         break;
1748 #ifdef  RSS
1749                                 case IPV6_RSS_LISTEN_BUCKET:
1750                                         if ((optval >= 0) &&
1751                                             (optval < rss_getnumbuckets())) {
1752                                                 INP_WLOCK(in6p);
1753                                                 in6p->inp_rss_listen_bucket = optval;
1754                                                 OPTSET2_N(INP_RSS_BUCKET_SET, 1);
1755                                                 INP_WUNLOCK(in6p);
1756                                         } else {
1757                                                 error = EINVAL;
1758                                         }
1759                                         break;
1760 #endif
1761                                 }
1762                                 break;
1763
1764                         case IPV6_TCLASS:
1765                         case IPV6_DONTFRAG:
1766                         case IPV6_USE_MIN_MTU:
1767                         case IPV6_PREFER_TEMPADDR:
1768                                 if (optlen != sizeof(optval)) {
1769                                         error = EINVAL;
1770                                         break;
1771                                 }
1772                                 error = sooptcopyin(sopt, &optval,
1773                                         sizeof optval, sizeof optval);
1774                                 if (error)
1775                                         break;
1776                                 {
1777                                         struct ip6_pktopts **optp;
1778                                         INP_WLOCK(in6p);
1779                                         if (in6p->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1780                                                 INP_WUNLOCK(in6p);
1781                                                 return (ECONNRESET);
1782                                         }
1783                                         optp = &in6p->in6p_outputopts;
1784                                         error = ip6_pcbopt(optname,
1785                                             (u_char *)&optval, sizeof(optval),
1786                                             optp, (td != NULL) ? td->td_ucred :
1787                                             NULL, uproto);
1788                                         INP_WUNLOCK(in6p);
1789                                         break;
1790                                 }
1791
1792                         case IPV6_2292PKTINFO:
1793                         case IPV6_2292HOPLIMIT:
1794                         case IPV6_2292HOPOPTS:
1795                         case IPV6_2292DSTOPTS:
1796                         case IPV6_2292RTHDR:
1797                                 /* RFC 2292 */
1798                                 if (optlen != sizeof(int)) {
1799                                         error = EINVAL;
1800                                         break;
1801                                 }
1802                                 error = sooptcopyin(sopt, &optval,
1803                                         sizeof optval, sizeof optval);
1804                                 if (error)
1805                                         break;
1806                                 switch (optname) {
1807                                 case IPV6_2292PKTINFO:
1808                                         OPTSET2292(IN6P_PKTINFO);
1809                                         break;
1810                                 case IPV6_2292HOPLIMIT:
1811                                         OPTSET2292(IN6P_HOPLIMIT);
1812                                         break;
1813                                 case IPV6_2292HOPOPTS:
1814                                         /*
1815                                          * Check super-user privilege.
1816                                          * See comments for IPV6_RECVHOPOPTS.
1817                                          */
1818                                         if (td != NULL) {
1819                                                 error = priv_check(td,
1820                                                     PRIV_NETINET_SETHDROPTS);
1821                                                 if (error)
1822                                                         return (error);
1823                                         }
1824                                         OPTSET2292(IN6P_HOPOPTS);
1825                                         break;
1826                                 case IPV6_2292DSTOPTS:
1827                                         if (td != NULL) {
1828                                                 error = priv_check(td,
1829                                                     PRIV_NETINET_SETHDROPTS);
1830                                                 if (error)
1831                                                         return (error);
1832                                         }
1833                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1834                                         break;
1835                                 case IPV6_2292RTHDR:
1836                                         OPTSET2292(IN6P_RTHDR);
1837                                         break;
1838                                 }
1839                                 break;
1840                         case IPV6_PKTINFO:
1841                         case IPV6_HOPOPTS:
1842                         case IPV6_RTHDR:
1843                         case IPV6_DSTOPTS:
1844                         case IPV6_RTHDRDSTOPTS:
1845                         case IPV6_NEXTHOP:
1846                         {
1847                                 /* new advanced API (RFC3542) */
1848                                 u_char *optbuf;
1849                                 u_char optbuf_storage[MCLBYTES];
1850                                 int optlen;
1851                                 struct ip6_pktopts **optp;
1852
1853                                 /* cannot mix with RFC2292 */
1854                                 if (OPTBIT(IN6P_RFC2292)) {
1855                                         error = EINVAL;
1856                                         break;
1857                                 }
1858
1859                                 /*
1860                                  * We only ensure valsize is not too large
1861                                  * here.  Further validation will be done
1862                                  * later.
1863                                  */
1864                                 error = sooptcopyin(sopt, optbuf_storage,
1865                                     sizeof(optbuf_storage), 0);
1866                                 if (error)
1867                                         break;
1868                                 optlen = sopt->sopt_valsize;
1869                                 optbuf = optbuf_storage;
1870                                 INP_WLOCK(in6p);
1871                                 if (in6p->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1872                                         INP_WUNLOCK(in6p);
1873                                         return (ECONNRESET);
1874                                 }
1875                                 optp = &in6p->in6p_outputopts;
1876                                 error = ip6_pcbopt(optname, optbuf, optlen,
1877                                     optp, (td != NULL) ? td->td_ucred : NULL,
1878                                     uproto);
1879                                 INP_WUNLOCK(in6p);
1880                                 break;
1881                         }
1882 #undef OPTSET
1883
1884                         case IPV6_MULTICAST_IF:
1885                         case IPV6_MULTICAST_HOPS:
1886                         case IPV6_MULTICAST_LOOP:
1887                         case IPV6_JOIN_GROUP:
1888                         case IPV6_LEAVE_GROUP:
1889                         case IPV6_MSFILTER:
1890                         case MCAST_BLOCK_SOURCE:
1891                         case MCAST_UNBLOCK_SOURCE:
1892                         case MCAST_JOIN_GROUP:
1893                         case MCAST_LEAVE_GROUP:
1894                         case MCAST_JOIN_SOURCE_GROUP:
1895                         case MCAST_LEAVE_SOURCE_GROUP:
1896                                 error = ip6_setmoptions(in6p, sopt);
1897                                 break;
1898
1899                         case IPV6_PORTRANGE:
1900                                 error = sooptcopyin(sopt, &optval,
1901                                     sizeof optval, sizeof optval);
1902                                 if (error)
1903                                         break;
1904
1905                                 INP_WLOCK(in6p);
1906                                 switch (optval) {
1907                                 case IPV6_PORTRANGE_DEFAULT:
1908                                         in6p->inp_flags &= ~(INP_LOWPORT);
1909                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1910                                         break;
1911
1912                                 case IPV6_PORTRANGE_HIGH:
1913                                         in6p->inp_flags &= ~(INP_LOWPORT);
1914                                         in6p->inp_flags |= INP_HIGHPORT;
1915                                         break;
1916
1917                                 case IPV6_PORTRANGE_LOW:
1918                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1919                                         in6p->inp_flags |= INP_LOWPORT;
1920                                         break;
1921
1922                                 default:
1923                                         error = EINVAL;
1924                                         break;
1925                                 }
1926                                 INP_WUNLOCK(in6p);
1927                                 break;
1928
1929 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1930                         case IPV6_IPSEC_POLICY:
1931                                 if (IPSEC_ENABLED(ipv6)) {
1932                                         error = IPSEC_PCBCTL(ipv6, in6p, sopt);
1933                                         break;
1934                                 }
1935                                 /* FALLTHROUGH */
1936 #endif /* IPSEC */
1937
1938                         default:
1939                                 error = ENOPROTOOPT;
1940                                 break;
1941                         }
1942                         break;
1943
1944                 case SOPT_GET:
1945                         switch (optname) {
1946
1947                         case IPV6_2292PKTOPTIONS:
1948 #ifdef IPV6_PKTOPTIONS
1949                         case IPV6_PKTOPTIONS:
1950 #endif
1951                                 /*
1952                                  * RFC3542 (effectively) deprecated the
1953                                  * semantics of the 2292-style pktoptions.
1954                                  * Since it was not reliable in nature (i.e.,
1955                                  * applications had to expect the lack of some
1956                                  * information after all), it would make sense
1957                                  * to simplify this part by always returning
1958                                  * empty data.
1959                                  */
1960                                 sopt->sopt_valsize = 0;
1961                                 break;
1962
1963                         case IPV6_RECVHOPOPTS:
1964                         case IPV6_RECVDSTOPTS:
1965                         case IPV6_RECVRTHDRDSTOPTS:
1966                         case IPV6_UNICAST_HOPS:
1967                         case IPV6_RECVPKTINFO:
1968                         case IPV6_RECVHOPLIMIT:
1969                         case IPV6_RECVRTHDR:
1970                         case IPV6_RECVPATHMTU:
1971
1972                         case IPV6_V6ONLY:
1973                         case IPV6_PORTRANGE:
1974                         case IPV6_RECVTCLASS:
1975                         case IPV6_AUTOFLOWLABEL:
1976                         case IPV6_BINDANY:
1977                         case IPV6_FLOWID:
1978                         case IPV6_FLOWTYPE:
1979                         case IPV6_RECVFLOWID:
1980 #ifdef  RSS
1981                         case IPV6_RSSBUCKETID:
1982                         case IPV6_RECVRSSBUCKETID:
1983 #endif
1984                         case IPV6_BINDMULTI:
1985                                 switch (optname) {
1986
1987                                 case IPV6_RECVHOPOPTS:
1988                                         optval = OPTBIT(IN6P_HOPOPTS);
1989                                         break;
1990
1991                                 case IPV6_RECVDSTOPTS:
1992                                         optval = OPTBIT(IN6P_DSTOPTS);
1993                                         break;
1994
1995                                 case IPV6_RECVRTHDRDSTOPTS:
1996                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1997                                         break;
1998
1999                                 case IPV6_UNICAST_HOPS:
2000                                         optval = in6p->in6p_hops;
2001                                         break;
2002
2003                                 case IPV6_RECVPKTINFO:
2004                                         optval = OPTBIT(IN6P_PKTINFO);
2005                                         break;
2006
2007                                 case IPV6_RECVHOPLIMIT:
2008                                         optval = OPTBIT(IN6P_HOPLIMIT);
2009                                         break;
2010
2011                                 case IPV6_RECVRTHDR:
2012                                         optval = OPTBIT(IN6P_RTHDR);
2013                                         break;
2014
2015                                 case IPV6_RECVPATHMTU:
2016                                         optval = OPTBIT(IN6P_MTU);
2017                                         break;
2018
2019                                 case IPV6_V6ONLY:
2020                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
2021                                         break;
2022
2023                                 case IPV6_PORTRANGE:
2024                                     {
2025                                         int flags;
2026                                         flags = in6p->inp_flags;
2027                                         if (flags & INP_HIGHPORT)
2028                                                 optval = IPV6_PORTRANGE_HIGH;
2029                                         else if (flags & INP_LOWPORT)
2030                                                 optval = IPV6_PORTRANGE_LOW;
2031                                         else
2032                                                 optval = 0;
2033                                         break;
2034                                     }
2035                                 case IPV6_RECVTCLASS:
2036                                         optval = OPTBIT(IN6P_TCLASS);
2037                                         break;
2038
2039                                 case IPV6_AUTOFLOWLABEL:
2040                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2041                                         break;
2042
2043                                 case IPV6_ORIGDSTADDR:
2044                                         optval = OPTBIT2(INP_ORIGDSTADDR);
2045                                         break;
2046
2047                                 case IPV6_BINDANY:
2048                                         optval = OPTBIT(INP_BINDANY);
2049                                         break;
2050
2051                                 case IPV6_FLOWID:
2052                                         optval = in6p->inp_flowid;
2053                                         break;
2054
2055                                 case IPV6_FLOWTYPE:
2056                                         optval = in6p->inp_flowtype;
2057                                         break;
2058
2059                                 case IPV6_RECVFLOWID:
2060                                         optval = OPTBIT2(INP_RECVFLOWID);
2061                                         break;
2062 #ifdef  RSS
2063                                 case IPV6_RSSBUCKETID:
2064                                         retval =
2065                                             rss_hash2bucket(in6p->inp_flowid,
2066                                             in6p->inp_flowtype,
2067                                             &rss_bucket);
2068                                         if (retval == 0)
2069                                                 optval = rss_bucket;
2070                                         else
2071                                                 error = EINVAL;
2072                                         break;
2073
2074                                 case IPV6_RECVRSSBUCKETID:
2075                                         optval = OPTBIT2(INP_RECVRSSBUCKETID);
2076                                         break;
2077 #endif
2078
2079                                 case IPV6_BINDMULTI:
2080                                         optval = OPTBIT2(INP_BINDMULTI);
2081                                         break;
2082
2083                                 }
2084                                 if (error)
2085                                         break;
2086                                 error = sooptcopyout(sopt, &optval,
2087                                         sizeof optval);
2088                                 break;
2089
2090                         case IPV6_PATHMTU:
2091                         {
2092                                 u_long pmtu = 0;
2093                                 struct ip6_mtuinfo mtuinfo;
2094                                 struct in6_addr addr;
2095
2096                                 if (!(so->so_state & SS_ISCONNECTED))
2097                                         return (ENOTCONN);
2098                                 /*
2099                                  * XXX: we dot not consider the case of source
2100                                  * routing, or optional information to specify
2101                                  * the outgoing interface.
2102                                  * Copy faddr out of in6p to avoid holding lock
2103                                  * on inp during route lookup.
2104                                  */
2105                                 INP_RLOCK(in6p);
2106                                 bcopy(&in6p->in6p_faddr, &addr, sizeof(addr));
2107                                 INP_RUNLOCK(in6p);
2108                                 error = ip6_getpmtu_ctl(so->so_fibnum,
2109                                     &addr, &pmtu);
2110                                 if (error)
2111                                         break;
2112                                 if (pmtu > IPV6_MAXPACKET)
2113                                         pmtu = IPV6_MAXPACKET;
2114
2115                                 bzero(&mtuinfo, sizeof(mtuinfo));
2116                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2117                                 optdata = (void *)&mtuinfo;
2118                                 optdatalen = sizeof(mtuinfo);
2119                                 error = sooptcopyout(sopt, optdata,
2120                                     optdatalen);
2121                                 break;
2122                         }
2123
2124                         case IPV6_2292PKTINFO:
2125                         case IPV6_2292HOPLIMIT:
2126                         case IPV6_2292HOPOPTS:
2127                         case IPV6_2292RTHDR:
2128                         case IPV6_2292DSTOPTS:
2129                                 switch (optname) {
2130                                 case IPV6_2292PKTINFO:
2131                                         optval = OPTBIT(IN6P_PKTINFO);
2132                                         break;
2133                                 case IPV6_2292HOPLIMIT:
2134                                         optval = OPTBIT(IN6P_HOPLIMIT);
2135                                         break;
2136                                 case IPV6_2292HOPOPTS:
2137                                         optval = OPTBIT(IN6P_HOPOPTS);
2138                                         break;
2139                                 case IPV6_2292RTHDR:
2140                                         optval = OPTBIT(IN6P_RTHDR);
2141                                         break;
2142                                 case IPV6_2292DSTOPTS:
2143                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2144                                         break;
2145                                 }
2146                                 error = sooptcopyout(sopt, &optval,
2147                                     sizeof optval);
2148                                 break;
2149                         case IPV6_PKTINFO:
2150                         case IPV6_HOPOPTS:
2151                         case IPV6_RTHDR:
2152                         case IPV6_DSTOPTS:
2153                         case IPV6_RTHDRDSTOPTS:
2154                         case IPV6_NEXTHOP:
2155                         case IPV6_TCLASS:
2156                         case IPV6_DONTFRAG:
2157                         case IPV6_USE_MIN_MTU:
2158                         case IPV6_PREFER_TEMPADDR:
2159                                 error = ip6_getpcbopt(in6p, optname, sopt);
2160                                 break;
2161
2162                         case IPV6_MULTICAST_IF:
2163                         case IPV6_MULTICAST_HOPS:
2164                         case IPV6_MULTICAST_LOOP:
2165                         case IPV6_MSFILTER:
2166                                 error = ip6_getmoptions(in6p, sopt);
2167                                 break;
2168
2169 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2170                         case IPV6_IPSEC_POLICY:
2171                                 if (IPSEC_ENABLED(ipv6)) {
2172                                         error = IPSEC_PCBCTL(ipv6, in6p, sopt);
2173                                         break;
2174                                 }
2175                                 /* FALLTHROUGH */
2176 #endif /* IPSEC */
2177                         default:
2178                                 error = ENOPROTOOPT;
2179                                 break;
2180                         }
2181                         break;
2182                 }
2183         }
2184         return (error);
2185 }
2186
2187 int
2188 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2189 {
2190         int error = 0, optval, optlen;
2191         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2192         struct inpcb *in6p = sotoinpcb(so);
2193         int level, op, optname;
2194
2195         level = sopt->sopt_level;
2196         op = sopt->sopt_dir;
2197         optname = sopt->sopt_name;
2198         optlen = sopt->sopt_valsize;
2199
2200         if (level != IPPROTO_IPV6) {
2201                 return (EINVAL);
2202         }
2203
2204         switch (optname) {
2205         case IPV6_CHECKSUM:
2206                 /*
2207                  * For ICMPv6 sockets, no modification allowed for checksum
2208                  * offset, permit "no change" values to help existing apps.
2209                  *
2210                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2211                  * for an ICMPv6 socket will fail."
2212                  * The current behavior does not meet RFC3542.
2213                  */
2214                 switch (op) {
2215                 case SOPT_SET:
2216                         if (optlen != sizeof(int)) {
2217                                 error = EINVAL;
2218                                 break;
2219                         }
2220                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2221                                             sizeof(optval));
2222                         if (error)
2223                                 break;
2224                         if ((optval % 2) != 0) {
2225                                 /* the API assumes even offset values */
2226                                 error = EINVAL;
2227                         } else if (so->so_proto->pr_protocol ==
2228                             IPPROTO_ICMPV6) {
2229                                 if (optval != icmp6off)
2230                                         error = EINVAL;
2231                         } else
2232                                 in6p->in6p_cksum = optval;
2233                         break;
2234
2235                 case SOPT_GET:
2236                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2237                                 optval = icmp6off;
2238                         else
2239                                 optval = in6p->in6p_cksum;
2240
2241                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2242                         break;
2243
2244                 default:
2245                         error = EINVAL;
2246                         break;
2247                 }
2248                 break;
2249
2250         default:
2251                 error = ENOPROTOOPT;
2252                 break;
2253         }
2254
2255         return (error);
2256 }
2257
2258 /*
2259  * Set up IP6 options in pcb for insertion in output packets or
2260  * specifying behavior of outgoing packets.
2261  */
2262 static int
2263 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2264     struct socket *so, struct sockopt *sopt)
2265 {
2266         struct ip6_pktopts *opt = *pktopt;
2267         int error = 0;
2268         struct thread *td = sopt->sopt_td;
2269
2270         /* turn off any old options. */
2271         if (opt) {
2272 #ifdef DIAGNOSTIC
2273                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2274                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2275                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2276                         printf("ip6_pcbopts: all specified options are cleared.\n");
2277 #endif
2278                 ip6_clearpktopts(opt, -1);
2279         } else
2280                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2281         *pktopt = NULL;
2282
2283         if (!m || m->m_len == 0) {
2284                 /*
2285                  * Only turning off any previous options, regardless of
2286                  * whether the opt is just created or given.
2287                  */
2288                 free(opt, M_IP6OPT);
2289                 return (0);
2290         }
2291
2292         /*  set options specified by user. */
2293         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2294             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2295                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2296                 free(opt, M_IP6OPT);
2297                 return (error);
2298         }
2299         *pktopt = opt;
2300         return (0);
2301 }
2302
2303 /*
2304  * initialize ip6_pktopts.  beware that there are non-zero default values in
2305  * the struct.
2306  */
2307 void
2308 ip6_initpktopts(struct ip6_pktopts *opt)
2309 {
2310
2311         bzero(opt, sizeof(*opt));
2312         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2313         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2314         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2315         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2316 }
2317
2318 static int
2319 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2320     struct ucred *cred, int uproto)
2321 {
2322         struct ip6_pktopts *opt;
2323
2324         if (*pktopt == NULL) {
2325                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2326                     M_NOWAIT);
2327                 if (*pktopt == NULL)
2328                         return (ENOBUFS);
2329                 ip6_initpktopts(*pktopt);
2330         }
2331         opt = *pktopt;
2332
2333         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2334 }
2335
2336 #define GET_PKTOPT_VAR(field, lenexpr) do {                                     \
2337         if (pktopt && pktopt->field) {                                          \
2338                 INP_RUNLOCK(in6p);                                              \
2339                 optdata = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK);         \
2340                 malloc_optdata = true;                                          \
2341                 INP_RLOCK(in6p);                                                \
2342                 if (in6p->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {           \
2343                         INP_RUNLOCK(in6p);                                      \
2344                         free(optdata, M_TEMP);                                  \
2345                         return (ECONNRESET);                                    \
2346                 }                                                               \
2347                 pktopt = in6p->in6p_outputopts;                                 \
2348                 if (pktopt && pktopt->field) {                                  \
2349                         optdatalen = min(lenexpr, sopt->sopt_valsize);          \
2350                         bcopy(&pktopt->field, optdata, optdatalen);             \
2351                 } else {                                                        \
2352                         free(optdata, M_TEMP);                                  \
2353                         optdata = NULL;                                         \
2354                         malloc_optdata = false;                                 \
2355                 }                                                               \
2356         }                                                                       \
2357 } while(0)
2358
2359 #define GET_PKTOPT_EXT_HDR(field) GET_PKTOPT_VAR(field,                         \
2360         (((struct ip6_ext *)pktopt->field)->ip6e_len + 1) << 3)
2361
2362 #define GET_PKTOPT_SOCKADDR(field) GET_PKTOPT_VAR(field,                        \
2363         pktopt->field->sa_len)
2364
2365 static int
2366 ip6_getpcbopt(struct inpcb *in6p, int optname, struct sockopt *sopt)
2367 {
2368         void *optdata = NULL;
2369         bool malloc_optdata = false;
2370         int optdatalen = 0;
2371         int error = 0;
2372         struct in6_pktinfo null_pktinfo;
2373         int deftclass = 0, on;
2374         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2375         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2376         struct ip6_pktopts *pktopt;
2377
2378         INP_RLOCK(in6p);
2379         pktopt = in6p->in6p_outputopts;
2380
2381         switch (optname) {
2382         case IPV6_PKTINFO:
2383                 optdata = (void *)&null_pktinfo;
2384                 if (pktopt && pktopt->ip6po_pktinfo) {
2385                         bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2386                             sizeof(null_pktinfo));
2387                         in6_clearscope(&null_pktinfo.ipi6_addr);
2388                 } else {
2389                         /* XXX: we don't have to do this every time... */
2390                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2391                 }
2392                 optdatalen = sizeof(struct in6_pktinfo);
2393                 break;
2394         case IPV6_TCLASS:
2395                 if (pktopt && pktopt->ip6po_tclass >= 0)
2396                         deftclass = pktopt->ip6po_tclass;
2397                 optdata = (void *)&deftclass;
2398                 optdatalen = sizeof(int);
2399                 break;
2400         case IPV6_HOPOPTS:
2401                 GET_PKTOPT_EXT_HDR(ip6po_hbh);
2402                 break;
2403         case IPV6_RTHDR:
2404                 GET_PKTOPT_EXT_HDR(ip6po_rthdr);
2405                 break;
2406         case IPV6_RTHDRDSTOPTS:
2407                 GET_PKTOPT_EXT_HDR(ip6po_dest1);
2408                 break;
2409         case IPV6_DSTOPTS:
2410                 GET_PKTOPT_EXT_HDR(ip6po_dest2);
2411                 break;
2412         case IPV6_NEXTHOP:
2413                 GET_PKTOPT_SOCKADDR(ip6po_nexthop);
2414                 break;
2415         case IPV6_USE_MIN_MTU:
2416                 if (pktopt)
2417                         defminmtu = pktopt->ip6po_minmtu;
2418                 optdata = (void *)&defminmtu;
2419                 optdatalen = sizeof(int);
2420                 break;
2421         case IPV6_DONTFRAG:
2422                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2423                         on = 1;
2424                 else
2425                         on = 0;
2426                 optdata = (void *)&on;
2427                 optdatalen = sizeof(on);
2428                 break;
2429         case IPV6_PREFER_TEMPADDR:
2430                 if (pktopt)
2431                         defpreftemp = pktopt->ip6po_prefer_tempaddr;
2432                 optdata = (void *)&defpreftemp;
2433                 optdatalen = sizeof(int);
2434                 break;
2435         default:                /* should not happen */
2436 #ifdef DIAGNOSTIC
2437                 panic("ip6_getpcbopt: unexpected option\n");
2438 #endif
2439                 INP_RUNLOCK(in6p);
2440                 return (ENOPROTOOPT);
2441         }
2442         INP_RUNLOCK(in6p);
2443
2444         error = sooptcopyout(sopt, optdata, optdatalen);
2445         if (malloc_optdata)
2446                 free(optdata, M_TEMP);
2447
2448         return (error);
2449 }
2450
2451 void
2452 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2453 {
2454         if (pktopt == NULL)
2455                 return;
2456
2457         if (optname == -1 || optname == IPV6_PKTINFO) {
2458                 if (pktopt->ip6po_pktinfo)
2459                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2460                 pktopt->ip6po_pktinfo = NULL;
2461         }
2462         if (optname == -1 || optname == IPV6_HOPLIMIT)
2463                 pktopt->ip6po_hlim = -1;
2464         if (optname == -1 || optname == IPV6_TCLASS)
2465                 pktopt->ip6po_tclass = -1;
2466         if (optname == -1 || optname == IPV6_NEXTHOP) {
2467                 if (pktopt->ip6po_nextroute.ro_rt) {
2468                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2469                         pktopt->ip6po_nextroute.ro_rt = NULL;
2470                 }
2471                 if (pktopt->ip6po_nexthop)
2472                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2473                 pktopt->ip6po_nexthop = NULL;
2474         }
2475         if (optname == -1 || optname == IPV6_HOPOPTS) {
2476                 if (pktopt->ip6po_hbh)
2477                         free(pktopt->ip6po_hbh, M_IP6OPT);
2478                 pktopt->ip6po_hbh = NULL;
2479         }
2480         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2481                 if (pktopt->ip6po_dest1)
2482                         free(pktopt->ip6po_dest1, M_IP6OPT);
2483                 pktopt->ip6po_dest1 = NULL;
2484         }
2485         if (optname == -1 || optname == IPV6_RTHDR) {
2486                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2487                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2488                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2489                 if (pktopt->ip6po_route.ro_rt) {
2490                         RTFREE(pktopt->ip6po_route.ro_rt);
2491                         pktopt->ip6po_route.ro_rt = NULL;
2492                 }
2493         }
2494         if (optname == -1 || optname == IPV6_DSTOPTS) {
2495                 if (pktopt->ip6po_dest2)
2496                         free(pktopt->ip6po_dest2, M_IP6OPT);
2497                 pktopt->ip6po_dest2 = NULL;
2498         }
2499 }
2500
2501 #define PKTOPT_EXTHDRCPY(type) \
2502 do {\
2503         if (src->type) {\
2504                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2505                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2506                 if (dst->type == NULL)\
2507                         goto bad;\
2508                 bcopy(src->type, dst->type, hlen);\
2509         }\
2510 } while (/*CONSTCOND*/ 0)
2511
2512 static int
2513 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2514 {
2515         if (dst == NULL || src == NULL)  {
2516                 printf("ip6_clearpktopts: invalid argument\n");
2517                 return (EINVAL);
2518         }
2519
2520         dst->ip6po_hlim = src->ip6po_hlim;
2521         dst->ip6po_tclass = src->ip6po_tclass;
2522         dst->ip6po_flags = src->ip6po_flags;
2523         dst->ip6po_minmtu = src->ip6po_minmtu;
2524         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2525         if (src->ip6po_pktinfo) {
2526                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2527                     M_IP6OPT, canwait);
2528                 if (dst->ip6po_pktinfo == NULL)
2529                         goto bad;
2530                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2531         }
2532         if (src->ip6po_nexthop) {
2533                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2534                     M_IP6OPT, canwait);
2535                 if (dst->ip6po_nexthop == NULL)
2536                         goto bad;
2537                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2538                     src->ip6po_nexthop->sa_len);
2539         }
2540         PKTOPT_EXTHDRCPY(ip6po_hbh);
2541         PKTOPT_EXTHDRCPY(ip6po_dest1);
2542         PKTOPT_EXTHDRCPY(ip6po_dest2);
2543         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2544         return (0);
2545
2546   bad:
2547         ip6_clearpktopts(dst, -1);
2548         return (ENOBUFS);
2549 }
2550 #undef PKTOPT_EXTHDRCPY
2551
2552 struct ip6_pktopts *
2553 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2554 {
2555         int error;
2556         struct ip6_pktopts *dst;
2557
2558         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2559         if (dst == NULL)
2560                 return (NULL);
2561         ip6_initpktopts(dst);
2562
2563         if ((error = copypktopts(dst, src, canwait)) != 0) {
2564                 free(dst, M_IP6OPT);
2565                 return (NULL);
2566         }
2567
2568         return (dst);
2569 }
2570
2571 void
2572 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2573 {
2574         if (pktopt == NULL)
2575                 return;
2576
2577         ip6_clearpktopts(pktopt, -1);
2578
2579         free(pktopt, M_IP6OPT);
2580 }
2581
2582 /*
2583  * Set IPv6 outgoing packet options based on advanced API.
2584  */
2585 int
2586 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2587     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2588 {
2589         struct cmsghdr *cm = NULL;
2590
2591         if (control == NULL || opt == NULL)
2592                 return (EINVAL);
2593
2594         ip6_initpktopts(opt);
2595         if (stickyopt) {
2596                 int error;
2597
2598                 /*
2599                  * If stickyopt is provided, make a local copy of the options
2600                  * for this particular packet, then override them by ancillary
2601                  * objects.
2602                  * XXX: copypktopts() does not copy the cached route to a next
2603                  * hop (if any).  This is not very good in terms of efficiency,
2604                  * but we can allow this since this option should be rarely
2605                  * used.
2606                  */
2607                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2608                         return (error);
2609         }
2610
2611         /*
2612          * XXX: Currently, we assume all the optional information is stored
2613          * in a single mbuf.
2614          */
2615         if (control->m_next)
2616                 return (EINVAL);
2617
2618         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2619             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2620                 int error;
2621
2622                 if (control->m_len < CMSG_LEN(0))
2623                         return (EINVAL);
2624
2625                 cm = mtod(control, struct cmsghdr *);
2626                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2627                         return (EINVAL);
2628                 if (cm->cmsg_level != IPPROTO_IPV6)
2629                         continue;
2630
2631                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2632                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2633                 if (error)
2634                         return (error);
2635         }
2636
2637         return (0);
2638 }
2639
2640 /*
2641  * Set a particular packet option, as a sticky option or an ancillary data
2642  * item.  "len" can be 0 only when it's a sticky option.
2643  * We have 4 cases of combination of "sticky" and "cmsg":
2644  * "sticky=0, cmsg=0": impossible
2645  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2646  * "sticky=1, cmsg=0": RFC3542 socket option
2647  * "sticky=1, cmsg=1": RFC2292 socket option
2648  */
2649 static int
2650 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2651     struct ucred *cred, int sticky, int cmsg, int uproto)
2652 {
2653         int minmtupolicy, preftemp;
2654         int error;
2655
2656         if (!sticky && !cmsg) {
2657 #ifdef DIAGNOSTIC
2658                 printf("ip6_setpktopt: impossible case\n");
2659 #endif
2660                 return (EINVAL);
2661         }
2662
2663         /*
2664          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2665          * not be specified in the context of RFC3542.  Conversely,
2666          * RFC3542 types should not be specified in the context of RFC2292.
2667          */
2668         if (!cmsg) {
2669                 switch (optname) {
2670                 case IPV6_2292PKTINFO:
2671                 case IPV6_2292HOPLIMIT:
2672                 case IPV6_2292NEXTHOP:
2673                 case IPV6_2292HOPOPTS:
2674                 case IPV6_2292DSTOPTS:
2675                 case IPV6_2292RTHDR:
2676                 case IPV6_2292PKTOPTIONS:
2677                         return (ENOPROTOOPT);
2678                 }
2679         }
2680         if (sticky && cmsg) {
2681                 switch (optname) {
2682                 case IPV6_PKTINFO:
2683                 case IPV6_HOPLIMIT:
2684                 case IPV6_NEXTHOP:
2685                 case IPV6_HOPOPTS:
2686                 case IPV6_DSTOPTS:
2687                 case IPV6_RTHDRDSTOPTS:
2688                 case IPV6_RTHDR:
2689                 case IPV6_USE_MIN_MTU:
2690                 case IPV6_DONTFRAG:
2691                 case IPV6_TCLASS:
2692                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2693                         return (ENOPROTOOPT);
2694                 }
2695         }
2696
2697         switch (optname) {
2698         case IPV6_2292PKTINFO:
2699         case IPV6_PKTINFO:
2700         {
2701                 struct ifnet *ifp = NULL;
2702                 struct in6_pktinfo *pktinfo;
2703
2704                 if (len != sizeof(struct in6_pktinfo))
2705                         return (EINVAL);
2706
2707                 pktinfo = (struct in6_pktinfo *)buf;
2708
2709                 /*
2710                  * An application can clear any sticky IPV6_PKTINFO option by
2711                  * doing a "regular" setsockopt with ipi6_addr being
2712                  * in6addr_any and ipi6_ifindex being zero.
2713                  * [RFC 3542, Section 6]
2714                  */
2715                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2716                     pktinfo->ipi6_ifindex == 0 &&
2717                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2718                         ip6_clearpktopts(opt, optname);
2719                         break;
2720                 }
2721
2722                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2723                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2724                         return (EINVAL);
2725                 }
2726                 if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2727                         return (EINVAL);
2728                 /* validate the interface index if specified. */
2729                 if (pktinfo->ipi6_ifindex > V_if_index)
2730                          return (ENXIO);
2731                 if (pktinfo->ipi6_ifindex) {
2732                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2733                         if (ifp == NULL)
2734                                 return (ENXIO);
2735                 }
2736                 if (ifp != NULL && (ifp->if_afdata[AF_INET6] == NULL ||
2737                     (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0))
2738                         return (ENETDOWN);
2739
2740                 if (ifp != NULL &&
2741                     !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2742                         struct in6_ifaddr *ia;
2743
2744                         in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2745                         ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2746                         if (ia == NULL)
2747                                 return (EADDRNOTAVAIL);
2748                         ifa_free(&ia->ia_ifa);
2749                 }
2750                 /*
2751                  * We store the address anyway, and let in6_selectsrc()
2752                  * validate the specified address.  This is because ipi6_addr
2753                  * may not have enough information about its scope zone, and
2754                  * we may need additional information (such as outgoing
2755                  * interface or the scope zone of a destination address) to
2756                  * disambiguate the scope.
2757                  * XXX: the delay of the validation may confuse the
2758                  * application when it is used as a sticky option.
2759                  */
2760                 if (opt->ip6po_pktinfo == NULL) {
2761                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2762                             M_IP6OPT, M_NOWAIT);
2763                         if (opt->ip6po_pktinfo == NULL)
2764                                 return (ENOBUFS);
2765                 }
2766                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2767                 break;
2768         }
2769
2770         case IPV6_2292HOPLIMIT:
2771         case IPV6_HOPLIMIT:
2772         {
2773                 int *hlimp;
2774
2775                 /*
2776                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2777                  * to simplify the ordering among hoplimit options.
2778                  */
2779                 if (optname == IPV6_HOPLIMIT && sticky)
2780                         return (ENOPROTOOPT);
2781
2782                 if (len != sizeof(int))
2783                         return (EINVAL);
2784                 hlimp = (int *)buf;
2785                 if (*hlimp < -1 || *hlimp > 255)
2786                         return (EINVAL);
2787
2788                 opt->ip6po_hlim = *hlimp;
2789                 break;
2790         }
2791
2792         case IPV6_TCLASS:
2793         {
2794                 int tclass;
2795
2796                 if (len != sizeof(int))
2797                         return (EINVAL);
2798                 tclass = *(int *)buf;
2799                 if (tclass < -1 || tclass > 255)
2800                         return (EINVAL);
2801
2802                 opt->ip6po_tclass = tclass;
2803                 break;
2804         }
2805
2806         case IPV6_2292NEXTHOP:
2807         case IPV6_NEXTHOP:
2808                 if (cred != NULL) {
2809                         error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
2810                         if (error)
2811                                 return (error);
2812                 }
2813
2814                 if (len == 0) { /* just remove the option */
2815                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2816                         break;
2817                 }
2818
2819                 /* check if cmsg_len is large enough for sa_len */
2820                 if (len < sizeof(struct sockaddr) || len < *buf)
2821                         return (EINVAL);
2822
2823                 switch (((struct sockaddr *)buf)->sa_family) {
2824                 case AF_INET6:
2825                 {
2826                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2827                         int error;
2828
2829                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2830                                 return (EINVAL);
2831
2832                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2833                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2834                                 return (EINVAL);
2835                         }
2836                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2837                             != 0) {
2838                                 return (error);
2839                         }
2840                         break;
2841                 }
2842                 case AF_LINK:   /* should eventually be supported */
2843                 default:
2844                         return (EAFNOSUPPORT);
2845                 }
2846
2847                 /* turn off the previous option, then set the new option. */
2848                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2849                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2850                 if (opt->ip6po_nexthop == NULL)
2851                         return (ENOBUFS);
2852                 bcopy(buf, opt->ip6po_nexthop, *buf);
2853                 break;
2854
2855         case IPV6_2292HOPOPTS:
2856         case IPV6_HOPOPTS:
2857         {
2858                 struct ip6_hbh *hbh;
2859                 int hbhlen;
2860
2861                 /*
2862                  * XXX: We don't allow a non-privileged user to set ANY HbH
2863                  * options, since per-option restriction has too much
2864                  * overhead.
2865                  */
2866                 if (cred != NULL) {
2867                         error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
2868                         if (error)
2869                                 return (error);
2870                 }
2871
2872                 if (len == 0) {
2873                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2874                         break;  /* just remove the option */
2875                 }
2876
2877                 /* message length validation */
2878                 if (len < sizeof(struct ip6_hbh))
2879                         return (EINVAL);
2880                 hbh = (struct ip6_hbh *)buf;
2881                 hbhlen = (hbh->ip6h_len + 1) << 3;
2882                 if (len != hbhlen)
2883                         return (EINVAL);
2884
2885                 /* turn off the previous option, then set the new option. */
2886                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2887                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2888                 if (opt->ip6po_hbh == NULL)
2889                         return (ENOBUFS);
2890                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2891
2892                 break;
2893         }
2894
2895         case IPV6_2292DSTOPTS:
2896         case IPV6_DSTOPTS:
2897         case IPV6_RTHDRDSTOPTS:
2898         {
2899                 struct ip6_dest *dest, **newdest = NULL;
2900                 int destlen;
2901
2902                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2903                         error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
2904                         if (error)
2905                                 return (error);
2906                 }
2907
2908                 if (len == 0) {
2909                         ip6_clearpktopts(opt, optname);
2910                         break;  /* just remove the option */
2911                 }
2912
2913                 /* message length validation */
2914                 if (len < sizeof(struct ip6_dest))
2915                         return (EINVAL);
2916                 dest = (struct ip6_dest *)buf;
2917                 destlen = (dest->ip6d_len + 1) << 3;
2918                 if (len != destlen)
2919                         return (EINVAL);
2920
2921                 /*
2922                  * Determine the position that the destination options header
2923                  * should be inserted; before or after the routing header.
2924                  */
2925                 switch (optname) {
2926                 case IPV6_2292DSTOPTS:
2927                         /*
2928                          * The old advacned API is ambiguous on this point.
2929                          * Our approach is to determine the position based
2930                          * according to the existence of a routing header.
2931                          * Note, however, that this depends on the order of the
2932                          * extension headers in the ancillary data; the 1st
2933                          * part of the destination options header must appear
2934                          * before the routing header in the ancillary data,
2935                          * too.
2936                          * RFC3542 solved the ambiguity by introducing
2937                          * separate ancillary data or option types.
2938                          */
2939                         if (opt->ip6po_rthdr == NULL)
2940                                 newdest = &opt->ip6po_dest1;
2941                         else
2942                                 newdest = &opt->ip6po_dest2;
2943                         break;
2944                 case IPV6_RTHDRDSTOPTS:
2945                         newdest = &opt->ip6po_dest1;
2946                         break;
2947                 case IPV6_DSTOPTS:
2948                         newdest = &opt->ip6po_dest2;
2949                         break;
2950                 }
2951
2952                 /* turn off the previous option, then set the new option. */
2953                 ip6_clearpktopts(opt, optname);
2954                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2955                 if (*newdest == NULL)
2956                         return (ENOBUFS);
2957                 bcopy(dest, *newdest, destlen);
2958
2959                 break;
2960         }
2961
2962         case IPV6_2292RTHDR:
2963         case IPV6_RTHDR:
2964         {
2965                 struct ip6_rthdr *rth;
2966                 int rthlen;
2967
2968                 if (len == 0) {
2969                         ip6_clearpktopts(opt, IPV6_RTHDR);
2970                         break;  /* just remove the option */
2971                 }
2972
2973                 /* message length validation */
2974                 if (len < sizeof(struct ip6_rthdr))
2975                         return (EINVAL);
2976                 rth = (struct ip6_rthdr *)buf;
2977                 rthlen = (rth->ip6r_len + 1) << 3;
2978                 if (len != rthlen)
2979                         return (EINVAL);
2980
2981                 switch (rth->ip6r_type) {
2982                 case IPV6_RTHDR_TYPE_0:
2983                         if (rth->ip6r_len == 0) /* must contain one addr */
2984                                 return (EINVAL);
2985                         if (rth->ip6r_len % 2) /* length must be even */
2986                                 return (EINVAL);
2987                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2988                                 return (EINVAL);
2989                         break;
2990                 default:
2991                         return (EINVAL);        /* not supported */
2992                 }
2993
2994                 /* turn off the previous option */
2995                 ip6_clearpktopts(opt, IPV6_RTHDR);
2996                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2997                 if (opt->ip6po_rthdr == NULL)
2998                         return (ENOBUFS);
2999                 bcopy(rth, opt->ip6po_rthdr, rthlen);
3000
3001                 break;
3002         }
3003
3004         case IPV6_USE_MIN_MTU:
3005                 if (len != sizeof(int))
3006                         return (EINVAL);
3007                 minmtupolicy = *(int *)buf;
3008                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3009                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
3010                     minmtupolicy != IP6PO_MINMTU_ALL) {
3011                         return (EINVAL);
3012                 }
3013                 opt->ip6po_minmtu = minmtupolicy;
3014                 break;
3015
3016         case IPV6_DONTFRAG:
3017                 if (len != sizeof(int))
3018                         return (EINVAL);
3019
3020                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3021                         /*
3022                          * we ignore this option for TCP sockets.
3023                          * (RFC3542 leaves this case unspecified.)
3024                          */
3025                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3026                 } else
3027                         opt->ip6po_flags |= IP6PO_DONTFRAG;
3028                 break;
3029
3030         case IPV6_PREFER_TEMPADDR:
3031                 if (len != sizeof(int))
3032                         return (EINVAL);
3033                 preftemp = *(int *)buf;
3034                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3035                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3036                     preftemp != IP6PO_TEMPADDR_PREFER) {
3037                         return (EINVAL);
3038                 }
3039                 opt->ip6po_prefer_tempaddr = preftemp;
3040                 break;
3041
3042         default:
3043                 return (ENOPROTOOPT);
3044         } /* end of switch */
3045
3046         return (0);
3047 }
3048
3049 /*
3050  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3051  * packet to the input queue of a specified interface.  Note that this
3052  * calls the output routine of the loopback "driver", but with an interface
3053  * pointer that might NOT be &loif -- easier than replicating that code here.
3054  */
3055 void
3056 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
3057 {
3058         struct mbuf *copym;
3059         struct ip6_hdr *ip6;
3060
3061         copym = m_copym(m, 0, M_COPYALL, M_NOWAIT);
3062         if (copym == NULL)
3063                 return;
3064
3065         /*
3066          * Make sure to deep-copy IPv6 header portion in case the data
3067          * is in an mbuf cluster, so that we can safely override the IPv6
3068          * header portion later.
3069          */
3070         if (!M_WRITABLE(copym) ||
3071             copym->m_len < sizeof(struct ip6_hdr)) {
3072                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3073                 if (copym == NULL)
3074                         return;
3075         }
3076         ip6 = mtod(copym, struct ip6_hdr *);
3077         /*
3078          * clear embedded scope identifiers if necessary.
3079          * in6_clearscope will touch the addresses only when necessary.
3080          */
3081         in6_clearscope(&ip6->ip6_src);
3082         in6_clearscope(&ip6->ip6_dst);
3083         if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3084                 copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3085                     CSUM_PSEUDO_HDR;
3086                 copym->m_pkthdr.csum_data = 0xffff;
3087         }
3088         if_simloop(ifp, copym, AF_INET6, 0);
3089 }
3090
3091 /*
3092  * Chop IPv6 header off from the payload.
3093  */
3094 static int
3095 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3096 {
3097         struct mbuf *mh;
3098         struct ip6_hdr *ip6;
3099
3100         ip6 = mtod(m, struct ip6_hdr *);
3101         if (m->m_len > sizeof(*ip6)) {
3102                 mh = m_gethdr(M_NOWAIT, MT_DATA);
3103                 if (mh == NULL) {
3104                         m_freem(m);
3105                         return ENOBUFS;
3106                 }
3107                 m_move_pkthdr(mh, m);
3108                 M_ALIGN(mh, sizeof(*ip6));
3109                 m->m_len -= sizeof(*ip6);
3110                 m->m_data += sizeof(*ip6);
3111                 mh->m_next = m;
3112                 m = mh;
3113                 m->m_len = sizeof(*ip6);
3114                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3115         }
3116         exthdrs->ip6e_ip6 = m;
3117         return 0;
3118 }
3119
3120 /*
3121  * Compute IPv6 extension header length.
3122  */
3123 int
3124 ip6_optlen(struct inpcb *in6p)
3125 {
3126         int len;
3127
3128         if (!in6p->in6p_outputopts)
3129                 return 0;
3130
3131         len = 0;
3132 #define elen(x) \
3133     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3134
3135         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3136         if (in6p->in6p_outputopts->ip6po_rthdr)
3137                 /* dest1 is valid with rthdr only */
3138                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3139         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3140         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3141         return len;
3142 #undef elen
3143 }