The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/ip6_output.c

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    1 /*-
    2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. Neither the name of the project nor the names of its contributors
   14  *    may be used to endorse or promote products derived from this software
   15  *    without specific prior written permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  *
   29  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
   30  */
   31 
   32 /*-
   33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
   34  *      The Regents of the University of California.  All rights reserved.
   35  *
   36  * Redistribution and use in source and binary forms, with or without
   37  * modification, are permitted provided that the following conditions
   38  * are met:
   39  * 1. Redistributions of source code must retain the above copyright
   40  *    notice, this list of conditions and the following disclaimer.
   41  * 2. Redistributions in binary form must reproduce the above copyright
   42  *    notice, this list of conditions and the following disclaimer in the
   43  *    documentation and/or other materials provided with the distribution.
   44  * 4. Neither the name of the University nor the names of its contributors
   45  *    may be used to endorse or promote products derived from this software
   46  *    without specific prior written permission.
   47  *
   48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   58  * SUCH DAMAGE.
   59  *
   60  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
   61  */
   62 
   63 #include <sys/cdefs.h>
   64 __FBSDID("$FreeBSD: stable/7/sys/netinet6/ip6_output.c 239825 2012-08-29 12:44:17Z bz $");
   65 
   66 #include "opt_inet.h"
   67 #include "opt_inet6.h"
   68 #include "opt_ipsec.h"
   69 
   70 #include <sys/param.h>
   71 #include <sys/kernel.h>
   72 #include <sys/malloc.h>
   73 #include <sys/mbuf.h>
   74 #include <sys/errno.h>
   75 #include <sys/priv.h>
   76 #include <sys/proc.h>
   77 #include <sys/protosw.h>
   78 #include <sys/socket.h>
   79 #include <sys/socketvar.h>
   80 #include <sys/ucred.h>
   81 
   82 #include <net/if.h>
   83 #include <net/netisr.h>
   84 #include <net/route.h>
   85 #include <net/pfil.h>
   86 
   87 #include <netinet/in.h>
   88 #include <netinet/in_var.h>
   89 #include <netinet6/in6_var.h>
   90 #include <netinet/ip6.h>
   91 #include <netinet/icmp6.h>
   92 #include <netinet6/ip6_var.h>
   93 #include <netinet/in_pcb.h>
   94 #include <netinet/tcp_var.h>
   95 #include <netinet6/nd6.h>
   96 
   97 #ifdef IPSEC
   98 #include <netipsec/ipsec.h>
   99 #include <netipsec/ipsec6.h>
  100 #include <netipsec/key.h>
  101 #include <netinet6/ip6_ipsec.h>
  102 #endif /* IPSEC */
  103 
  104 #include <netinet6/ip6protosw.h>
  105 #include <netinet6/scope6_var.h>
  106 
  107 static MALLOC_DEFINE(M_IP6MOPTS, "ip6_moptions", "internet multicast options");
  108 
  109 struct ip6_exthdrs {
  110         struct mbuf *ip6e_ip6;
  111         struct mbuf *ip6e_hbh;
  112         struct mbuf *ip6e_dest1;
  113         struct mbuf *ip6e_rthdr;
  114         struct mbuf *ip6e_dest2;
  115 };
  116 
  117 static int ip6_pcbopt __P((int, u_char *, int, struct ip6_pktopts **,
  118                            struct ucred *, int));
  119 static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
  120         struct socket *, struct sockopt *));
  121 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
  122 static int ip6_setpktopt __P((int, u_char *, int, struct ip6_pktopts *,
  123         struct ucred *, int, int, int));
  124 
  125 static int ip6_setmoptions(int, struct ip6_moptions **, struct mbuf *);
  126 static int ip6_getmoptions(int, struct ip6_moptions *, struct mbuf **);
  127 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
  128 static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
  129         struct ip6_frag **));
  130 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
  131 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
  132 static int ip6_getpmtu __P((struct route_in6 *, struct route_in6 *,
  133         struct ifnet *, struct in6_addr *, u_long *, int *));
  134 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
  135 
  136 
  137 /*
  138  * Make an extension header from option data.  hp is the source, and
  139  * mp is the destination.
  140  */
  141 #define MAKE_EXTHDR(hp, mp)                                             \
  142     do {                                                                \
  143         if (hp) {                                                       \
  144                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
  145                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
  146                     ((eh)->ip6e_len + 1) << 3);                         \
  147                 if (error)                                              \
  148                         goto freehdrs;                                  \
  149         }                                                               \
  150     } while (/*CONSTCOND*/ 0)
  151 
  152 /*
  153  * Form a chain of extension headers.
  154  * m is the extension header mbuf
  155  * mp is the previous mbuf in the chain
  156  * p is the next header
  157  * i is the type of option.
  158  */
  159 #define MAKE_CHAIN(m, mp, p, i)\
  160     do {\
  161         if (m) {\
  162                 if (!hdrsplit) \
  163                         panic("assumption failed: hdr not split"); \
  164                 *mtod((m), u_char *) = *(p);\
  165                 *(p) = (i);\
  166                 p = mtod((m), u_char *);\
  167                 (m)->m_next = (mp)->m_next;\
  168                 (mp)->m_next = (m);\
  169                 (mp) = (m);\
  170         }\
  171     } while (/*CONSTCOND*/ 0)
  172 
  173 /*
  174  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
  175  * header (with pri, len, nxt, hlim, src, dst).
  176  * This function may modify ver and hlim only.
  177  * The mbuf chain containing the packet will be freed.
  178  * The mbuf opt, if present, will not be freed.
  179  *
  180  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
  181  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
  182  * which is rt_rmx.rmx_mtu.
  183  *
  184  * ifpp - XXX: just for statistics
  185  */
  186 int
  187 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
  188     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
  189     struct ifnet **ifpp, struct inpcb *inp)
  190 {
  191         struct ip6_hdr *ip6, *mhip6;
  192         struct ifnet *ifp, *origifp;
  193         struct mbuf *m = m0;
  194         struct mbuf *mprev = NULL;
  195         int hlen, tlen, len, off;
  196         struct route_in6 ip6route;
  197         struct rtentry *rt = NULL;
  198         struct sockaddr_in6 *dst, src_sa, dst_sa;
  199         struct in6_addr odst;
  200         int error = 0;
  201         struct in6_ifaddr *ia = NULL;
  202         u_long mtu;
  203         int alwaysfrag, dontfrag;
  204         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
  205         struct ip6_exthdrs exthdrs;
  206         struct in6_addr finaldst, src0, dst0;
  207         u_int32_t zone;
  208         struct route_in6 *ro_pmtu = NULL;
  209         int hdrsplit = 0;
  210         int needipsec = 0;
  211 #ifdef IPSEC
  212         struct ipsec_output_state state;
  213         struct ip6_rthdr *rh = NULL;
  214         int needipsectun = 0;
  215         int segleft_org = 0;
  216         struct secpolicy *sp = NULL;
  217 #endif /* IPSEC */
  218 
  219         ip6 = mtod(m, struct ip6_hdr *);
  220         if (ip6 == NULL) {
  221                 printf ("ip6 is NULL");
  222                 goto bad;
  223         }
  224 
  225         finaldst = ip6->ip6_dst;
  226 
  227         bzero(&exthdrs, sizeof(exthdrs));
  228 
  229         if (opt) {
  230                 /* Hop-by-Hop options header */
  231                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
  232                 /* Destination options header(1st part) */
  233                 if (opt->ip6po_rthdr) {
  234                         /*
  235                          * Destination options header(1st part)
  236                          * This only makes sense with a routing header.
  237                          * See Section 9.2 of RFC 3542.
  238                          * Disabling this part just for MIP6 convenience is
  239                          * a bad idea.  We need to think carefully about a
  240                          * way to make the advanced API coexist with MIP6
  241                          * options, which might automatically be inserted in
  242                          * the kernel.
  243                          */
  244                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
  245                 }
  246                 /* Routing header */
  247                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
  248                 /* Destination options header(2nd part) */
  249                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
  250         }
  251 
  252 #ifdef IPSEC
  253         /*
  254          * IPSec checking which handles several cases.
  255          * FAST IPSEC: We re-injected the packet.
  256          */
  257         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
  258         {
  259         case 1:                 /* Bad packet */
  260                 goto freehdrs;
  261         case -1:                /* Do IPSec */
  262                 needipsec = 1;
  263         case 0:                 /* No IPSec */
  264         default:
  265                 break;
  266         }
  267 #endif /* IPSEC */
  268 
  269         /*
  270          * Calculate the total length of the extension header chain.
  271          * Keep the length of the unfragmentable part for fragmentation.
  272          */
  273         optlen = 0;
  274         if (exthdrs.ip6e_hbh)
  275                 optlen += exthdrs.ip6e_hbh->m_len;
  276         if (exthdrs.ip6e_dest1)
  277                 optlen += exthdrs.ip6e_dest1->m_len;
  278         if (exthdrs.ip6e_rthdr)
  279                 optlen += exthdrs.ip6e_rthdr->m_len;
  280         unfragpartlen = optlen + sizeof(struct ip6_hdr);
  281 
  282         /* NOTE: we don't add AH/ESP length here. do that later. */
  283         if (exthdrs.ip6e_dest2)
  284                 optlen += exthdrs.ip6e_dest2->m_len;
  285 
  286         /*
  287          * If we need IPsec, or there is at least one extension header,
  288          * separate IP6 header from the payload.
  289          */
  290         if ((needipsec || optlen) && !hdrsplit) {
  291                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
  292                         m = NULL;
  293                         goto freehdrs;
  294                 }
  295                 m = exthdrs.ip6e_ip6;
  296                 hdrsplit++;
  297         }
  298 
  299         /* adjust pointer */
  300         ip6 = mtod(m, struct ip6_hdr *);
  301 
  302         /* adjust mbuf packet header length */
  303         m->m_pkthdr.len += optlen;
  304         plen = m->m_pkthdr.len - sizeof(*ip6);
  305 
  306         /* If this is a jumbo payload, insert a jumbo payload option. */
  307         if (plen > IPV6_MAXPACKET) {
  308                 if (!hdrsplit) {
  309                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
  310                                 m = NULL;
  311                                 goto freehdrs;
  312                         }
  313                         m = exthdrs.ip6e_ip6;
  314                         hdrsplit++;
  315                 }
  316                 /* adjust pointer */
  317                 ip6 = mtod(m, struct ip6_hdr *);
  318                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
  319                         goto freehdrs;
  320                 ip6->ip6_plen = 0;
  321         } else
  322                 ip6->ip6_plen = htons(plen);
  323 
  324         /*
  325          * Concatenate headers and fill in next header fields.
  326          * Here we have, on "m"
  327          *      IPv6 payload
  328          * and we insert headers accordingly.  Finally, we should be getting:
  329          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
  330          *
  331          * during the header composing process, "m" points to IPv6 header.
  332          * "mprev" points to an extension header prior to esp.
  333          */
  334         u_char *nexthdrp = &ip6->ip6_nxt;
  335         mprev = m;
  336 
  337         /*
  338          * we treat dest2 specially.  this makes IPsec processing
  339          * much easier.  the goal here is to make mprev point the
  340          * mbuf prior to dest2.
  341          *
  342          * result: IPv6 dest2 payload
  343          * m and mprev will point to IPv6 header.
  344          */
  345         if (exthdrs.ip6e_dest2) {
  346                 if (!hdrsplit)
  347                         panic("assumption failed: hdr not split");
  348                 exthdrs.ip6e_dest2->m_next = m->m_next;
  349                 m->m_next = exthdrs.ip6e_dest2;
  350                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
  351                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
  352         }
  353 
  354         /*
  355          * result: IPv6 hbh dest1 rthdr dest2 payload
  356          * m will point to IPv6 header.  mprev will point to the
  357          * extension header prior to dest2 (rthdr in the above case).
  358          */
  359         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
  360         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
  361                    IPPROTO_DSTOPTS);
  362         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
  363                    IPPROTO_ROUTING);
  364 
  365 #ifdef IPSEC
  366         if (!needipsec)
  367                 goto skip_ipsec2;
  368 
  369         /*
  370          * pointers after IPsec headers are not valid any more.
  371          * other pointers need a great care too.
  372          * (IPsec routines should not mangle mbufs prior to AH/ESP)
  373          */
  374         exthdrs.ip6e_dest2 = NULL;
  375 
  376         if (exthdrs.ip6e_rthdr) {
  377                 rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
  378                 segleft_org = rh->ip6r_segleft;
  379                 rh->ip6r_segleft = 0;
  380         }
  381 
  382         bzero(&state, sizeof(state));
  383         state.m = m;
  384         error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
  385                                     &needipsectun);
  386         m = state.m;
  387         if (error == EJUSTRETURN) {
  388                 /*
  389                  * We had a SP with a level of 'use' and no SA. We
  390                  * will just continue to process the packet without
  391                  * IPsec processing.
  392                  */
  393                 ;
  394         } else if (error) {
  395                 /* mbuf is already reclaimed in ipsec6_output_trans. */
  396                 m = NULL;
  397                 switch (error) {
  398                 case EHOSTUNREACH:
  399                 case ENETUNREACH:
  400                 case EMSGSIZE:
  401                 case ENOBUFS:
  402                 case ENOMEM:
  403                         break;
  404                 default:
  405                         printf("[%s:%d] (ipsec): error code %d\n",
  406                             __func__, __LINE__, error);
  407                         /* FALLTHROUGH */
  408                 case ENOENT:
  409                         /* don't show these error codes to the user */
  410                         error = 0;
  411                         break;
  412                 }
  413                 goto bad;
  414         } else if (!needipsectun) {
  415                 /*
  416                  * In the FAST IPSec case we have already
  417                  * re-injected the packet and it has been freed
  418                  * by the ipsec_done() function.  So, just clean
  419                  * up after ourselves.
  420                  */
  421                 m = NULL;
  422                 goto done;
  423         }
  424         if (exthdrs.ip6e_rthdr) {
  425                 /* ah6_output doesn't modify mbuf chain */
  426                 rh->ip6r_segleft = segleft_org;
  427         }
  428 skip_ipsec2:;
  429 #endif /* IPSEC */
  430 
  431         /*
  432          * If there is a routing header, replace the destination address field
  433          * with the first hop of the routing header.
  434          */
  435         if (exthdrs.ip6e_rthdr) {
  436                 struct ip6_rthdr *rh =
  437                         (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
  438                                                   struct ip6_rthdr *));
  439                 struct ip6_rthdr0 *rh0;
  440                 struct in6_addr *addr;
  441                 struct sockaddr_in6 sa;
  442 
  443                 switch (rh->ip6r_type) {
  444                 case IPV6_RTHDR_TYPE_0:
  445                          rh0 = (struct ip6_rthdr0 *)rh;
  446                          addr = (struct in6_addr *)(rh0 + 1);
  447 
  448                          /*
  449                           * construct a sockaddr_in6 form of
  450                           * the first hop.
  451                           *
  452                           * XXX: we may not have enough
  453                           * information about its scope zone;
  454                           * there is no standard API to pass
  455                           * the information from the
  456                           * application.
  457                           */
  458                          bzero(&sa, sizeof(sa));
  459                          sa.sin6_family = AF_INET6;
  460                          sa.sin6_len = sizeof(sa);
  461                          sa.sin6_addr = addr[0];
  462                          if ((error = sa6_embedscope(&sa,
  463                              ip6_use_defzone)) != 0) {
  464                                  goto bad;
  465                          }
  466                          ip6->ip6_dst = sa.sin6_addr;
  467                          bcopy(&addr[1], &addr[0], sizeof(struct in6_addr)
  468                              * (rh0->ip6r0_segleft - 1));
  469                          addr[rh0->ip6r0_segleft - 1] = finaldst;
  470                          /* XXX */
  471                          in6_clearscope(addr + rh0->ip6r0_segleft - 1);
  472                          break;
  473                 default:        /* is it possible? */
  474                          error = EINVAL;
  475                          goto bad;
  476                 }
  477         }
  478 
  479         /* Source address validation */
  480         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
  481             (flags & IPV6_UNSPECSRC) == 0) {
  482                 error = EOPNOTSUPP;
  483                 ip6stat.ip6s_badscope++;
  484                 goto bad;
  485         }
  486         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
  487                 error = EOPNOTSUPP;
  488                 ip6stat.ip6s_badscope++;
  489                 goto bad;
  490         }
  491 
  492         ip6stat.ip6s_localout++;
  493 
  494         /*
  495          * Route packet.
  496          */
  497         if (ro == 0) {
  498                 ro = &ip6route;
  499                 bzero((caddr_t)ro, sizeof(*ro));
  500         }
  501         ro_pmtu = ro;
  502         if (opt && opt->ip6po_rthdr)
  503                 ro = &opt->ip6po_route;
  504         dst = (struct sockaddr_in6 *)&ro->ro_dst;
  505 
  506 again:
  507         /*
  508          * if specified, try to fill in the traffic class field.
  509          * do not override if a non-zero value is already set.
  510          * we check the diffserv field and the ecn field separately.
  511          */
  512         if (opt && opt->ip6po_tclass >= 0) {
  513                 int mask = 0;
  514 
  515                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
  516                         mask |= 0xfc;
  517                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
  518                         mask |= 0x03;
  519                 if (mask != 0)
  520                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
  521         }
  522 
  523         /* fill in or override the hop limit field, if necessary. */
  524         if (opt && opt->ip6po_hlim != -1)
  525                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
  526         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
  527                 if (im6o != NULL)
  528                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
  529                 else
  530                         ip6->ip6_hlim = ip6_defmcasthlim;
  531         }
  532 
  533 #ifdef IPSEC
  534         /*
  535          * We may re-inject packets into the stack here.
  536          */
  537         if (needipsec && needipsectun) {
  538                 struct ipsec_output_state state;
  539 
  540                 /*
  541                  * All the extension headers will become inaccessible
  542                  * (since they can be encrypted).
  543                  * Don't panic, we need no more updates to extension headers
  544                  * on inner IPv6 packet (since they are now encapsulated).
  545                  *
  546                  * IPv6 [ESP|AH] IPv6 [extension headers] payload
  547                  */
  548                 bzero(&exthdrs, sizeof(exthdrs));
  549                 exthdrs.ip6e_ip6 = m;
  550 
  551                 bzero(&state, sizeof(state));
  552                 state.m = m;
  553                 state.ro = (struct route *)ro;
  554                 state.dst = (struct sockaddr *)dst;
  555 
  556                 error = ipsec6_output_tunnel(&state, sp, flags);
  557 
  558                 m = state.m;
  559                 ro = (struct route_in6 *)state.ro;
  560                 dst = (struct sockaddr_in6 *)state.dst;
  561                 if (error == EJUSTRETURN) {
  562                         /*
  563                          * We had a SP with a level of 'use' and no SA. We
  564                          * will just continue to process the packet without
  565                          * IPsec processing.
  566                          */
  567                         ;
  568                 } else if (error) {
  569                         /* mbuf is already reclaimed in ipsec6_output_tunnel. */
  570                         m0 = m = NULL;
  571                         m = NULL;
  572                         switch (error) {
  573                         case EHOSTUNREACH:
  574                         case ENETUNREACH:
  575                         case EMSGSIZE:
  576                         case ENOBUFS:
  577                         case ENOMEM:
  578                                 break;
  579                         default:
  580                                 printf("[%s:%d] (ipsec): error code %d\n",
  581                                     __func__, __LINE__, error);
  582                                 /* FALLTHROUGH */
  583                         case ENOENT:
  584                                 /* don't show these error codes to the user */
  585                                 error = 0;
  586                                 break;
  587                         }
  588                         goto bad;
  589                 } else {
  590                         /*
  591                          * In the FAST IPSec case we have already
  592                          * re-injected the packet and it has been freed
  593                          * by the ipsec_done() function.  So, just clean
  594                          * up after ourselves.
  595                          */
  596                         m = NULL;
  597                         goto done;
  598                 }
  599 
  600                 exthdrs.ip6e_ip6 = m;
  601         }
  602 #endif /* IPSEC */
  603 
  604         /* adjust pointer */
  605         ip6 = mtod(m, struct ip6_hdr *);
  606 
  607         bzero(&dst_sa, sizeof(dst_sa));
  608         dst_sa.sin6_family = AF_INET6;
  609         dst_sa.sin6_len = sizeof(dst_sa);
  610         dst_sa.sin6_addr = ip6->ip6_dst;
  611         if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
  612             &ifp, &rt, 0)) != 0) {
  613                 switch (error) {
  614                 case EHOSTUNREACH:
  615                         ip6stat.ip6s_noroute++;
  616                         break;
  617                 case EADDRNOTAVAIL:
  618                 default:
  619                         break; /* XXX statistics? */
  620                 }
  621                 if (ifp != NULL)
  622                         in6_ifstat_inc(ifp, ifs6_out_discard);
  623                 goto bad;
  624         }
  625         if (rt == NULL) {
  626                 /*
  627                  * If in6_selectroute() does not return a route entry,
  628                  * dst may not have been updated.
  629                  */
  630                 *dst = dst_sa;  /* XXX */
  631         }
  632 
  633         /*
  634          * then rt (for unicast) and ifp must be non-NULL valid values.
  635          */
  636         if ((flags & IPV6_FORWARDING) == 0) {
  637                 /* XXX: the FORWARDING flag can be set for mrouting. */
  638                 in6_ifstat_inc(ifp, ifs6_out_request);
  639         }
  640         if (rt != NULL) {
  641                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
  642                 rt->rt_use++;
  643         }
  644 
  645         /*
  646          * The outgoing interface must be in the zone of source and
  647          * destination addresses.  We should use ia_ifp to support the
  648          * case of sending packets to an address of our own.
  649          */
  650         if (ia != NULL && ia->ia_ifp)
  651                 origifp = ia->ia_ifp;
  652         else
  653                 origifp = ifp;
  654 
  655         src0 = ip6->ip6_src;
  656         if (in6_setscope(&src0, origifp, &zone))
  657                 goto badscope;
  658         bzero(&src_sa, sizeof(src_sa));
  659         src_sa.sin6_family = AF_INET6;
  660         src_sa.sin6_len = sizeof(src_sa);
  661         src_sa.sin6_addr = ip6->ip6_src;
  662         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
  663                 goto badscope;
  664 
  665         dst0 = ip6->ip6_dst;
  666         if (in6_setscope(&dst0, origifp, &zone))
  667                 goto badscope;
  668         /* re-initialize to be sure */
  669         bzero(&dst_sa, sizeof(dst_sa));
  670         dst_sa.sin6_family = AF_INET6;
  671         dst_sa.sin6_len = sizeof(dst_sa);
  672         dst_sa.sin6_addr = ip6->ip6_dst;
  673         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
  674                 goto badscope;
  675         }
  676 
  677         /* scope check is done. */
  678         goto routefound;
  679 
  680   badscope:
  681         ip6stat.ip6s_badscope++;
  682         in6_ifstat_inc(origifp, ifs6_out_discard);
  683         if (error == 0)
  684                 error = EHOSTUNREACH; /* XXX */
  685         goto bad;
  686 
  687   routefound:
  688         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
  689                 if (opt && opt->ip6po_nextroute.ro_rt) {
  690                         /*
  691                          * The nexthop is explicitly specified by the
  692                          * application.  We assume the next hop is an IPv6
  693                          * address.
  694                          */
  695                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
  696                 }
  697                 else if ((rt->rt_flags & RTF_GATEWAY))
  698                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
  699         }
  700 
  701         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
  702                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
  703         } else {
  704                 struct  in6_multi *in6m;
  705 
  706                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
  707 
  708                 in6_ifstat_inc(ifp, ifs6_out_mcast);
  709 
  710                 /*
  711                  * Confirm that the outgoing interface supports multicast.
  712                  */
  713                 if (!(ifp->if_flags & IFF_MULTICAST)) {
  714                         ip6stat.ip6s_noroute++;
  715                         in6_ifstat_inc(ifp, ifs6_out_discard);
  716                         error = ENETUNREACH;
  717                         goto bad;
  718                 }
  719                 IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
  720                 if (in6m != NULL &&
  721                    (im6o == NULL || im6o->im6o_multicast_loop)) {
  722                         /*
  723                          * If we belong to the destination multicast group
  724                          * on the outgoing interface, and the caller did not
  725                          * forbid loopback, loop back a copy.
  726                          */
  727                         ip6_mloopback(ifp, m, dst);
  728                 } else {
  729                         /*
  730                          * If we are acting as a multicast router, perform
  731                          * multicast forwarding as if the packet had just
  732                          * arrived on the interface to which we are about
  733                          * to send.  The multicast forwarding function
  734                          * recursively calls this function, using the
  735                          * IPV6_FORWARDING flag to prevent infinite recursion.
  736                          *
  737                          * Multicasts that are looped back by ip6_mloopback(),
  738                          * above, will be forwarded by the ip6_input() routine,
  739                          * if necessary.
  740                          */
  741                         if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
  742                                 /*
  743                                  * XXX: ip6_mforward expects that rcvif is NULL
  744                                  * when it is called from the originating path.
  745                                  * However, it is not always the case, since
  746                                  * some versions of MGETHDR() does not
  747                                  * initialize the field.
  748                                  */
  749                                 m->m_pkthdr.rcvif = NULL;
  750                                 if (ip6_mforward(ip6, ifp, m) != 0) {
  751                                         m_freem(m);
  752                                         goto done;
  753                                 }
  754                         }
  755                 }
  756                 /*
  757                  * Multicasts with a hoplimit of zero may be looped back,
  758                  * above, but must not be transmitted on a network.
  759                  * Also, multicasts addressed to the loopback interface
  760                  * are not sent -- the above call to ip6_mloopback() will
  761                  * loop back a copy if this host actually belongs to the
  762                  * destination group on the loopback interface.
  763                  */
  764                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
  765                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
  766                         m_freem(m);
  767                         goto done;
  768                 }
  769         }
  770 
  771         /*
  772          * Fill the outgoing inteface to tell the upper layer
  773          * to increment per-interface statistics.
  774          */
  775         if (ifpp)
  776                 *ifpp = ifp;
  777 
  778         /* Determine path MTU. */
  779         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
  780             &alwaysfrag)) != 0)
  781                 goto bad;
  782 
  783         /*
  784          * The caller of this function may specify to use the minimum MTU
  785          * in some cases.
  786          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
  787          * setting.  The logic is a bit complicated; by default, unicast
  788          * packets will follow path MTU while multicast packets will be sent at
  789          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
  790          * including unicast ones will be sent at the minimum MTU.  Multicast
  791          * packets will always be sent at the minimum MTU unless
  792          * IP6PO_MINMTU_DISABLE is explicitly specified.
  793          * See RFC 3542 for more details.
  794          */
  795         if (mtu > IPV6_MMTU) {
  796                 if ((flags & IPV6_MINMTU))
  797                         mtu = IPV6_MMTU;
  798                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
  799                         mtu = IPV6_MMTU;
  800                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
  801                          (opt == NULL ||
  802                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
  803                         mtu = IPV6_MMTU;
  804                 }
  805         }
  806 
  807         /*
  808          * clear embedded scope identifiers if necessary.
  809          * in6_clearscope will touch the addresses only when necessary.
  810          */
  811         in6_clearscope(&ip6->ip6_src);
  812         in6_clearscope(&ip6->ip6_dst);
  813 
  814         /*
  815          * If the outgoing packet contains a hop-by-hop options header,
  816          * it must be examined and processed even by the source node.
  817          * (RFC 2460, section 4.)
  818          */
  819         if (exthdrs.ip6e_hbh) {
  820                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
  821                 u_int32_t dummy; /* XXX unused */
  822                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
  823 
  824 #ifdef DIAGNOSTIC
  825                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
  826                         panic("ip6e_hbh is not continuous");
  827 #endif
  828                 /*
  829                  *  XXX: if we have to send an ICMPv6 error to the sender,
  830                  *       we need the M_LOOP flag since icmp6_error() expects
  831                  *       the IPv6 and the hop-by-hop options header are
  832                  *       continuous unless the flag is set.
  833                  */
  834                 m->m_flags |= M_LOOP;
  835                 m->m_pkthdr.rcvif = ifp;
  836                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
  837                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
  838                     &dummy, &plen) < 0) {
  839                         /* m was already freed at this point */
  840                         error = EINVAL;/* better error? */
  841                         goto done;
  842                 }
  843                 m->m_flags &= ~M_LOOP; /* XXX */
  844                 m->m_pkthdr.rcvif = NULL;
  845         }
  846 
  847         /* Jump over all PFIL processing if hooks are not active. */
  848         if (!PFIL_HOOKED(&inet6_pfil_hook))
  849                 goto passout;
  850 
  851         odst = ip6->ip6_dst;
  852         /* Run through list of hooks for output packets. */
  853         error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
  854         if (error != 0 || m == NULL)
  855                 goto done;
  856         ip6 = mtod(m, struct ip6_hdr *);
  857 
  858         /* See if destination IP address was changed by packet filter. */
  859         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
  860                 m->m_flags |= M_SKIP_FIREWALL;
  861                 /* If destination is now ourself drop to ip6_input(). */
  862                 if (in6_localaddr(&ip6->ip6_dst)) {
  863                         if (m->m_pkthdr.rcvif == NULL)
  864                                 m->m_pkthdr.rcvif = loif;
  865                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
  866                                 m->m_pkthdr.csum_flags |=
  867                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
  868                                 m->m_pkthdr.csum_data = 0xffff;
  869                         }
  870                         m->m_pkthdr.csum_flags |=
  871                             CSUM_IP_CHECKED | CSUM_IP_VALID;
  872                         error = netisr_queue(NETISR_IPV6, m);
  873                         goto done;
  874                 } else
  875                         goto again;     /* Redo the routing table lookup. */
  876         }
  877 
  878         /* XXX: IPFIREWALL_FORWARD */
  879 
  880 passout:
  881         /*
  882          * Send the packet to the outgoing interface.
  883          * If necessary, do IPv6 fragmentation before sending.
  884          *
  885          * the logic here is rather complex:
  886          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
  887          * 1-a: send as is if tlen <= path mtu
  888          * 1-b: fragment if tlen > path mtu
  889          *
  890          * 2: if user asks us not to fragment (dontfrag == 1)
  891          * 2-a: send as is if tlen <= interface mtu
  892          * 2-b: error if tlen > interface mtu
  893          *
  894          * 3: if we always need to attach fragment header (alwaysfrag == 1)
  895          *      always fragment
  896          *
  897          * 4: if dontfrag == 1 && alwaysfrag == 1
  898          *      error, as we cannot handle this conflicting request
  899          */
  900         tlen = m->m_pkthdr.len;
  901 
  902         if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
  903                 dontfrag = 1;
  904         else
  905                 dontfrag = 0;
  906         if (dontfrag && alwaysfrag) {   /* case 4 */
  907                 /* conflicting request - can't transmit */
  908                 error = EMSGSIZE;
  909                 goto bad;
  910         }
  911         if (dontfrag && tlen > IN6_LINKMTU(ifp)) {      /* case 2-b */
  912                 /*
  913                  * Even if the DONTFRAG option is specified, we cannot send the
  914                  * packet when the data length is larger than the MTU of the
  915                  * outgoing interface.
  916                  * Notify the error by sending IPV6_PATHMTU ancillary data as
  917                  * well as returning an error code (the latter is not described
  918                  * in the API spec.)
  919                  */
  920                 u_int32_t mtu32;
  921                 struct ip6ctlparam ip6cp;
  922 
  923                 mtu32 = (u_int32_t)mtu;
  924                 bzero(&ip6cp, sizeof(ip6cp));
  925                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
  926                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
  927                     (void *)&ip6cp);
  928 
  929                 error = EMSGSIZE;
  930                 goto bad;
  931         }
  932 
  933         /*
  934          * transmit packet without fragmentation
  935          */
  936         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
  937                 struct in6_ifaddr *ia6;
  938 
  939                 ip6 = mtod(m, struct ip6_hdr *);
  940                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
  941                 if (ia6) {
  942                         /* Record statistics for this interface address. */
  943                         ia6->ia_ifa.if_opackets++;
  944                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
  945                 }
  946                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
  947                 goto done;
  948         }
  949 
  950         /*
  951          * try to fragment the packet.  case 1-b and 3
  952          */
  953         if (mtu < IPV6_MMTU) {
  954                 /* path MTU cannot be less than IPV6_MMTU */
  955                 error = EMSGSIZE;
  956                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
  957                 goto bad;
  958         } else if (ip6->ip6_plen == 0) {
  959                 /* jumbo payload cannot be fragmented */
  960                 error = EMSGSIZE;
  961                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
  962                 goto bad;
  963         } else {
  964                 struct mbuf **mnext, *m_frgpart;
  965                 struct ip6_frag *ip6f;
  966                 u_int32_t id = htonl(ip6_randomid());
  967                 u_char nextproto;
  968 
  969                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
  970 
  971                 /*
  972                  * Too large for the destination or interface;
  973                  * fragment if possible.
  974                  * Must be able to put at least 8 bytes per fragment.
  975                  */
  976                 hlen = unfragpartlen;
  977                 if (mtu > IPV6_MAXPACKET)
  978                         mtu = IPV6_MAXPACKET;
  979 
  980                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
  981                 if (len < 8) {
  982                         error = EMSGSIZE;
  983                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
  984                         goto bad;
  985                 }
  986 
  987                 /*
  988                  * Verify that we have any chance at all of being able to queue
  989                  *      the packet or packet fragments
  990                  */
  991                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
  992                     < tlen  /* - hlen */)) {
  993                         error = ENOBUFS;
  994                         ip6stat.ip6s_odropped++;
  995                         goto bad;
  996                 }
  997 
  998                 mnext = &m->m_nextpkt;
  999 
 1000                 /*
 1001                  * Change the next header field of the last header in the
 1002                  * unfragmentable part.
 1003                  */
 1004                 if (exthdrs.ip6e_rthdr) {
 1005                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
 1006                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
 1007                 } else if (exthdrs.ip6e_dest1) {
 1008                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
 1009                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
 1010                 } else if (exthdrs.ip6e_hbh) {
 1011                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
 1012                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
 1013                 } else {
 1014                         nextproto = ip6->ip6_nxt;
 1015                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
 1016                 }
 1017 
 1018                 /*
 1019                  * Loop through length of segment after first fragment,
 1020                  * make new header and copy data of each part and link onto
 1021                  * chain.
 1022                  */
 1023                 m0 = m;
 1024                 for (off = hlen; off < tlen; off += len) {
 1025                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
 1026                         if (!m) {
 1027                                 error = ENOBUFS;
 1028                                 ip6stat.ip6s_odropped++;
 1029                                 goto sendorfree;
 1030                         }
 1031                         m->m_pkthdr.rcvif = NULL;
 1032                         m->m_flags = m0->m_flags & M_COPYFLAGS;
 1033                         *mnext = m;
 1034                         mnext = &m->m_nextpkt;
 1035                         m->m_data += max_linkhdr;
 1036                         mhip6 = mtod(m, struct ip6_hdr *);
 1037                         *mhip6 = *ip6;
 1038                         m->m_len = sizeof(*mhip6);
 1039                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
 1040                         if (error) {
 1041                                 ip6stat.ip6s_odropped++;
 1042                                 goto sendorfree;
 1043                         }
 1044                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
 1045                         if (off + len >= tlen)
 1046                                 len = tlen - off;
 1047                         else
 1048                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
 1049                         mhip6->ip6_plen = htons((u_short)(len + hlen +
 1050                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
 1051                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
 1052                                 error = ENOBUFS;
 1053                                 ip6stat.ip6s_odropped++;
 1054                                 goto sendorfree;
 1055                         }
 1056                         m_cat(m, m_frgpart);
 1057                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
 1058                         m->m_pkthdr.rcvif = NULL;
 1059                         ip6f->ip6f_reserved = 0;
 1060                         ip6f->ip6f_ident = id;
 1061                         ip6f->ip6f_nxt = nextproto;
 1062                         ip6stat.ip6s_ofragments++;
 1063                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
 1064                 }
 1065 
 1066                 in6_ifstat_inc(ifp, ifs6_out_fragok);
 1067         }
 1068 
 1069         /*
 1070          * Remove leading garbages.
 1071          */
 1072 sendorfree:
 1073         m = m0->m_nextpkt;
 1074         m0->m_nextpkt = 0;
 1075         m_freem(m0);
 1076         for (m0 = m; m; m = m0) {
 1077                 m0 = m->m_nextpkt;
 1078                 m->m_nextpkt = 0;
 1079                 if (error == 0) {
 1080                         /* Record statistics for this interface address. */
 1081                         if (ia) {
 1082                                 ia->ia_ifa.if_opackets++;
 1083                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
 1084                         }
 1085                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
 1086                 } else
 1087                         m_freem(m);
 1088         }
 1089 
 1090         if (error == 0)
 1091                 ip6stat.ip6s_fragmented++;
 1092 
 1093 done:
 1094         if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
 1095                 RTFREE(ro->ro_rt);
 1096         } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
 1097                 RTFREE(ro_pmtu->ro_rt);
 1098         }
 1099 #ifdef IPSEC
 1100         if (sp != NULL)
 1101                 KEY_FREESP(&sp);
 1102 #endif
 1103 
 1104         return (error);
 1105 
 1106 freehdrs:
 1107         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
 1108         m_freem(exthdrs.ip6e_dest1);
 1109         m_freem(exthdrs.ip6e_rthdr);
 1110         m_freem(exthdrs.ip6e_dest2);
 1111         /* FALLTHROUGH */
 1112 bad:
 1113         if (m)
 1114                 m_freem(m);
 1115         goto done;
 1116 }
 1117 
 1118 static int
 1119 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
 1120 {
 1121         struct mbuf *m;
 1122 
 1123         if (hlen > MCLBYTES)
 1124                 return (ENOBUFS); /* XXX */
 1125 
 1126         MGET(m, M_DONTWAIT, MT_DATA);
 1127         if (!m)
 1128                 return (ENOBUFS);
 1129 
 1130         if (hlen > MLEN) {
 1131                 MCLGET(m, M_DONTWAIT);
 1132                 if ((m->m_flags & M_EXT) == 0) {
 1133                         m_free(m);
 1134                         return (ENOBUFS);
 1135                 }
 1136         }
 1137         m->m_len = hlen;
 1138         if (hdr)
 1139                 bcopy(hdr, mtod(m, caddr_t), hlen);
 1140 
 1141         *mp = m;
 1142         return (0);
 1143 }
 1144 
 1145 /*
 1146  * Insert jumbo payload option.
 1147  */
 1148 static int
 1149 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
 1150 {
 1151         struct mbuf *mopt;
 1152         u_char *optbuf;
 1153         u_int32_t v;
 1154 
 1155 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
 1156 
 1157         /*
 1158          * If there is no hop-by-hop options header, allocate new one.
 1159          * If there is one but it doesn't have enough space to store the
 1160          * jumbo payload option, allocate a cluster to store the whole options.
 1161          * Otherwise, use it to store the options.
 1162          */
 1163         if (exthdrs->ip6e_hbh == 0) {
 1164                 MGET(mopt, M_DONTWAIT, MT_DATA);
 1165                 if (mopt == 0)
 1166                         return (ENOBUFS);
 1167                 mopt->m_len = JUMBOOPTLEN;
 1168                 optbuf = mtod(mopt, u_char *);
 1169                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
 1170                 exthdrs->ip6e_hbh = mopt;
 1171         } else {
 1172                 struct ip6_hbh *hbh;
 1173 
 1174                 mopt = exthdrs->ip6e_hbh;
 1175                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
 1176                         /*
 1177                          * XXX assumption:
 1178                          * - exthdrs->ip6e_hbh is not referenced from places
 1179                          *   other than exthdrs.
 1180                          * - exthdrs->ip6e_hbh is not an mbuf chain.
 1181                          */
 1182                         int oldoptlen = mopt->m_len;
 1183                         struct mbuf *n;
 1184 
 1185                         /*
 1186                          * XXX: give up if the whole (new) hbh header does
 1187                          * not fit even in an mbuf cluster.
 1188                          */
 1189                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
 1190                                 return (ENOBUFS);
 1191 
 1192                         /*
 1193                          * As a consequence, we must always prepare a cluster
 1194                          * at this point.
 1195                          */
 1196                         MGET(n, M_DONTWAIT, MT_DATA);
 1197                         if (n) {
 1198                                 MCLGET(n, M_DONTWAIT);
 1199                                 if ((n->m_flags & M_EXT) == 0) {
 1200                                         m_freem(n);
 1201                                         n = NULL;
 1202                                 }
 1203                         }
 1204                         if (!n)
 1205                                 return (ENOBUFS);
 1206                         n->m_len = oldoptlen + JUMBOOPTLEN;
 1207                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
 1208                             oldoptlen);
 1209                         optbuf = mtod(n, caddr_t) + oldoptlen;
 1210                         m_freem(mopt);
 1211                         mopt = exthdrs->ip6e_hbh = n;
 1212                 } else {
 1213                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
 1214                         mopt->m_len += JUMBOOPTLEN;
 1215                 }
 1216                 optbuf[0] = IP6OPT_PADN;
 1217                 optbuf[1] = 1;
 1218 
 1219                 /*
 1220                  * Adjust the header length according to the pad and
 1221                  * the jumbo payload option.
 1222                  */
 1223                 hbh = mtod(mopt, struct ip6_hbh *);
 1224                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
 1225         }
 1226 
 1227         /* fill in the option. */
 1228         optbuf[2] = IP6OPT_JUMBO;
 1229         optbuf[3] = 4;
 1230         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
 1231         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
 1232 
 1233         /* finally, adjust the packet header length */
 1234         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
 1235 
 1236         return (0);
 1237 #undef JUMBOOPTLEN
 1238 }
 1239 
 1240 /*
 1241  * Insert fragment header and copy unfragmentable header portions.
 1242  */
 1243 static int
 1244 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
 1245     struct ip6_frag **frghdrp)
 1246 {
 1247         struct mbuf *n, *mlast;
 1248 
 1249         if (hlen > sizeof(struct ip6_hdr)) {
 1250                 n = m_copym(m0, sizeof(struct ip6_hdr),
 1251                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
 1252                 if (n == 0)
 1253                         return (ENOBUFS);
 1254                 m->m_next = n;
 1255         } else
 1256                 n = m;
 1257 
 1258         /* Search for the last mbuf of unfragmentable part. */
 1259         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
 1260                 ;
 1261 
 1262         if ((mlast->m_flags & M_EXT) == 0 &&
 1263             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
 1264                 /* use the trailing space of the last mbuf for the fragment hdr */
 1265                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
 1266                     mlast->m_len);
 1267                 mlast->m_len += sizeof(struct ip6_frag);
 1268                 m->m_pkthdr.len += sizeof(struct ip6_frag);
 1269         } else {
 1270                 /* allocate a new mbuf for the fragment header */
 1271                 struct mbuf *mfrg;
 1272 
 1273                 MGET(mfrg, M_DONTWAIT, MT_DATA);
 1274                 if (mfrg == 0)
 1275                         return (ENOBUFS);
 1276                 mfrg->m_len = sizeof(struct ip6_frag);
 1277                 *frghdrp = mtod(mfrg, struct ip6_frag *);
 1278                 mlast->m_next = mfrg;
 1279         }
 1280 
 1281         return (0);
 1282 }
 1283 
 1284 static int
 1285 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
 1286     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
 1287     int *alwaysfragp)
 1288 {
 1289         u_int32_t mtu = 0;
 1290         int alwaysfrag = 0;
 1291         int error = 0;
 1292 
 1293         if (ro_pmtu != ro) {
 1294                 /* The first hop and the final destination may differ. */
 1295                 struct sockaddr_in6 *sa6_dst =
 1296                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
 1297                 if (ro_pmtu->ro_rt &&
 1298                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
 1299                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
 1300                         RTFREE(ro_pmtu->ro_rt);
 1301                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
 1302                 }
 1303                 if (ro_pmtu->ro_rt == NULL) {
 1304                         bzero(sa6_dst, sizeof(*sa6_dst));
 1305                         sa6_dst->sin6_family = AF_INET6;
 1306                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
 1307                         sa6_dst->sin6_addr = *dst;
 1308 
 1309                         rtalloc((struct route *)ro_pmtu);
 1310                 }
 1311         }
 1312         if (ro_pmtu->ro_rt) {
 1313                 u_int32_t ifmtu;
 1314                 struct in_conninfo inc;
 1315 
 1316                 bzero(&inc, sizeof(inc));
 1317                 inc.inc_flags |= INC_ISIPV6;
 1318                 inc.inc6_faddr = *dst;
 1319 
 1320                 if (ifp == NULL)
 1321                         ifp = ro_pmtu->ro_rt->rt_ifp;
 1322                 ifmtu = IN6_LINKMTU(ifp);
 1323                 mtu = tcp_hc_getmtu(&inc);
 1324                 if (mtu)
 1325                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
 1326                 else
 1327                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
 1328                 if (mtu == 0)
 1329                         mtu = ifmtu;
 1330                 else if (mtu < IPV6_MMTU) {
 1331                         /*
 1332                          * RFC2460 section 5, last paragraph:
 1333                          * if we record ICMPv6 too big message with
 1334                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
 1335                          * or smaller, with framgent header attached.
 1336                          * (fragment header is needed regardless from the
 1337                          * packet size, for translators to identify packets)
 1338                          */
 1339                         alwaysfrag = 1;
 1340                         mtu = IPV6_MMTU;
 1341                 } else if (mtu > ifmtu) {
 1342                         /*
 1343                          * The MTU on the route is larger than the MTU on
 1344                          * the interface!  This shouldn't happen, unless the
 1345                          * MTU of the interface has been changed after the
 1346                          * interface was brought up.  Change the MTU in the
 1347                          * route to match the interface MTU (as long as the
 1348                          * field isn't locked).
 1349                          */
 1350                         mtu = ifmtu;
 1351                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
 1352                 }
 1353         } else if (ifp) {
 1354                 mtu = IN6_LINKMTU(ifp);
 1355         } else
 1356                 error = EHOSTUNREACH; /* XXX */
 1357 
 1358         *mtup = mtu;
 1359         if (alwaysfragp)
 1360                 *alwaysfragp = alwaysfrag;
 1361         return (error);
 1362 }
 1363 
 1364 /*
 1365  * IP6 socket option processing.
 1366  */
 1367 int
 1368 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
 1369 {
 1370         int optdatalen, uproto;
 1371         void *optdata;
 1372         struct inpcb *in6p = sotoinpcb(so);
 1373         int error, optval;
 1374         int level, op, optname;
 1375         int optlen;
 1376         struct thread *td;
 1377 
 1378         level = sopt->sopt_level;
 1379         op = sopt->sopt_dir;
 1380         optname = sopt->sopt_name;
 1381         optlen = sopt->sopt_valsize;
 1382         td = sopt->sopt_td;
 1383         error = 0;
 1384         optval = 0;
 1385         uproto = (int)so->so_proto->pr_protocol;
 1386 
 1387         if (level == IPPROTO_IPV6) {
 1388                 switch (op) {
 1389 
 1390                 case SOPT_SET:
 1391                         switch (optname) {
 1392                         case IPV6_2292PKTOPTIONS:
 1393 #ifdef IPV6_PKTOPTIONS
 1394                         case IPV6_PKTOPTIONS:
 1395 #endif
 1396                         {
 1397                                 struct mbuf *m;
 1398 
 1399                                 error = soopt_getm(sopt, &m); /* XXX */
 1400                                 if (error != 0)
 1401                                         break;
 1402                                 error = soopt_mcopyin(sopt, m); /* XXX */
 1403                                 if (error != 0)
 1404                                         break;
 1405                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
 1406                                                     m, so, sopt);
 1407                                 m_freem(m); /* XXX */
 1408                                 break;
 1409                         }
 1410 
 1411                         /*
 1412                          * Use of some Hop-by-Hop options or some
 1413                          * Destination options, might require special
 1414                          * privilege.  That is, normal applications
 1415                          * (without special privilege) might be forbidden
 1416                          * from setting certain options in outgoing packets,
 1417                          * and might never see certain options in received
 1418                          * packets. [RFC 2292 Section 6]
 1419                          * KAME specific note:
 1420                          *  KAME prevents non-privileged users from sending or
 1421                          *  receiving ANY hbh/dst options in order to avoid
 1422                          *  overhead of parsing options in the kernel.
 1423                          */
 1424                         case IPV6_RECVHOPOPTS:
 1425                         case IPV6_RECVDSTOPTS:
 1426                         case IPV6_RECVRTHDRDSTOPTS:
 1427                                 if (td != NULL) {
 1428                                         error = priv_check(td,
 1429                                             PRIV_NETINET_SETHDROPTS);
 1430                                         if (error)
 1431                                                 break;
 1432                                 }
 1433                                 /* FALLTHROUGH */
 1434                         case IPV6_UNICAST_HOPS:
 1435                         case IPV6_HOPLIMIT:
 1436                         case IPV6_FAITH:
 1437 
 1438                         case IPV6_RECVPKTINFO:
 1439                         case IPV6_RECVHOPLIMIT:
 1440                         case IPV6_RECVRTHDR:
 1441                         case IPV6_RECVPATHMTU:
 1442                         case IPV6_RECVTCLASS:
 1443                         case IPV6_V6ONLY:
 1444                         case IPV6_AUTOFLOWLABEL:
 1445                                 if (optlen != sizeof(int)) {
 1446                                         error = EINVAL;
 1447                                         break;
 1448                                 }
 1449                                 error = sooptcopyin(sopt, &optval,
 1450                                         sizeof optval, sizeof optval);
 1451                                 if (error)
 1452                                         break;
 1453                                 switch (optname) {
 1454 
 1455                                 case IPV6_UNICAST_HOPS:
 1456                                         if (optval < -1 || optval >= 256)
 1457                                                 error = EINVAL;
 1458                                         else {
 1459                                                 /* -1 = kernel default */
 1460                                                 in6p->in6p_hops = optval;
 1461                                                 if ((in6p->inp_vflag &
 1462                                                      INP_IPV4) != 0)
 1463                                                         in6p->inp_ip_ttl = optval;
 1464                                         }
 1465                                         break;
 1466 #define OPTSET(bit) \
 1467 do { \
 1468         if (optval) \
 1469                 in6p->inp_flags |= (bit); \
 1470         else \
 1471                 in6p->inp_flags &= ~(bit); \
 1472 } while (/*CONSTCOND*/ 0)
 1473 #define OPTSET2292(bit) \
 1474 do { \
 1475         in6p->inp_flags |= IN6P_RFC2292; \
 1476         if (optval) \
 1477                 in6p->inp_flags |= (bit); \
 1478         else \
 1479                 in6p->inp_flags &= ~(bit); \
 1480 } while (/*CONSTCOND*/ 0)
 1481 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
 1482 
 1483                                 case IPV6_RECVPKTINFO:
 1484                                         /* cannot mix with RFC2292 */
 1485                                         if (OPTBIT(IN6P_RFC2292)) {
 1486                                                 error = EINVAL;
 1487                                                 break;
 1488                                         }
 1489                                         OPTSET(IN6P_PKTINFO);
 1490                                         break;
 1491 
 1492                                 case IPV6_HOPLIMIT:
 1493                                 {
 1494                                         struct ip6_pktopts **optp;
 1495 
 1496                                         /* cannot mix with RFC2292 */
 1497                                         if (OPTBIT(IN6P_RFC2292)) {
 1498                                                 error = EINVAL;
 1499                                                 break;
 1500                                         }
 1501                                         optp = &in6p->in6p_outputopts;
 1502                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
 1503                                             (u_char *)&optval, sizeof(optval),
 1504                                             optp, (td != NULL) ? td->td_ucred :
 1505                                             NULL, uproto);
 1506                                         break;
 1507                                 }
 1508 
 1509                                 case IPV6_RECVHOPLIMIT:
 1510                                         /* cannot mix with RFC2292 */
 1511                                         if (OPTBIT(IN6P_RFC2292)) {
 1512                                                 error = EINVAL;
 1513                                                 break;
 1514                                         }
 1515                                         OPTSET(IN6P_HOPLIMIT);
 1516                                         break;
 1517 
 1518                                 case IPV6_RECVHOPOPTS:
 1519                                         /* cannot mix with RFC2292 */
 1520                                         if (OPTBIT(IN6P_RFC2292)) {
 1521                                                 error = EINVAL;
 1522                                                 break;
 1523                                         }
 1524                                         OPTSET(IN6P_HOPOPTS);
 1525                                         break;
 1526 
 1527                                 case IPV6_RECVDSTOPTS:
 1528                                         /* cannot mix with RFC2292 */
 1529                                         if (OPTBIT(IN6P_RFC2292)) {
 1530                                                 error = EINVAL;
 1531                                                 break;
 1532                                         }
 1533                                         OPTSET(IN6P_DSTOPTS);
 1534                                         break;
 1535 
 1536                                 case IPV6_RECVRTHDRDSTOPTS:
 1537                                         /* cannot mix with RFC2292 */
 1538                                         if (OPTBIT(IN6P_RFC2292)) {
 1539                                                 error = EINVAL;
 1540                                                 break;
 1541                                         }
 1542                                         OPTSET(IN6P_RTHDRDSTOPTS);
 1543                                         break;
 1544 
 1545                                 case IPV6_RECVRTHDR:
 1546                                         /* cannot mix with RFC2292 */
 1547                                         if (OPTBIT(IN6P_RFC2292)) {
 1548                                                 error = EINVAL;
 1549                                                 break;
 1550                                         }
 1551                                         OPTSET(IN6P_RTHDR);
 1552                                         break;
 1553 
 1554                                 case IPV6_FAITH:
 1555                                         OPTSET(INP_FAITH);
 1556                                         break;
 1557 
 1558                                 case IPV6_RECVPATHMTU:
 1559                                         /*
 1560                                          * We ignore this option for TCP
 1561                                          * sockets.
 1562                                          * (RFC3542 leaves this case
 1563                                          * unspecified.)
 1564                                          */
 1565                                         if (uproto != IPPROTO_TCP)
 1566                                                 OPTSET(IN6P_MTU);
 1567                                         break;
 1568 
 1569                                 case IPV6_V6ONLY:
 1570                                         /*
 1571                                          * make setsockopt(IPV6_V6ONLY)
 1572                                          * available only prior to bind(2).
 1573                                          * see ipng mailing list, Jun 22 2001.
 1574                                          */
 1575                                         if (in6p->inp_lport ||
 1576                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
 1577                                                 error = EINVAL;
 1578                                                 break;
 1579                                         }
 1580                                         OPTSET(IN6P_IPV6_V6ONLY);
 1581                                         if (optval)
 1582                                                 in6p->inp_vflag &= ~INP_IPV4;
 1583                                         else
 1584                                                 in6p->inp_vflag |= INP_IPV4;
 1585                                         break;
 1586                                 case IPV6_RECVTCLASS:
 1587                                         /* cannot mix with RFC2292 XXX */
 1588                                         if (OPTBIT(IN6P_RFC2292)) {
 1589                                                 error = EINVAL;
 1590                                                 break;
 1591                                         }
 1592                                         OPTSET(IN6P_TCLASS);
 1593                                         break;
 1594                                 case IPV6_AUTOFLOWLABEL:
 1595                                         OPTSET(IN6P_AUTOFLOWLABEL);
 1596                                         break;
 1597 
 1598                                 }
 1599                                 break;
 1600 
 1601                         case IPV6_TCLASS:
 1602                         case IPV6_DONTFRAG:
 1603                         case IPV6_USE_MIN_MTU:
 1604                         case IPV6_PREFER_TEMPADDR:
 1605                                 if (optlen != sizeof(optval)) {
 1606                                         error = EINVAL;
 1607                                         break;
 1608                                 }
 1609                                 error = sooptcopyin(sopt, &optval,
 1610                                         sizeof optval, sizeof optval);
 1611                                 if (error)
 1612                                         break;
 1613                                 {
 1614                                         struct ip6_pktopts **optp;
 1615                                         optp = &in6p->in6p_outputopts;
 1616                                         error = ip6_pcbopt(optname,
 1617                                             (u_char *)&optval, sizeof(optval),
 1618                                             optp, (td != NULL) ? td->td_ucred :
 1619                                             NULL, uproto);
 1620                                         break;
 1621                                 }
 1622 
 1623                         case IPV6_2292PKTINFO:
 1624                         case IPV6_2292HOPLIMIT:
 1625                         case IPV6_2292HOPOPTS:
 1626                         case IPV6_2292DSTOPTS:
 1627                         case IPV6_2292RTHDR:
 1628                                 /* RFC 2292 */
 1629                                 if (optlen != sizeof(int)) {
 1630                                         error = EINVAL;
 1631                                         break;
 1632                                 }
 1633                                 error = sooptcopyin(sopt, &optval,
 1634                                         sizeof optval, sizeof optval);
 1635                                 if (error)
 1636                                         break;
 1637                                 switch (optname) {
 1638                                 case IPV6_2292PKTINFO:
 1639                                         OPTSET2292(IN6P_PKTINFO);
 1640                                         break;
 1641                                 case IPV6_2292HOPLIMIT:
 1642                                         OPTSET2292(IN6P_HOPLIMIT);
 1643                                         break;
 1644                                 case IPV6_2292HOPOPTS:
 1645                                         /*
 1646                                          * Check super-user privilege.
 1647                                          * See comments for IPV6_RECVHOPOPTS.
 1648                                          */
 1649                                         if (td != NULL) {
 1650                                                 error = priv_check(td,
 1651                                                     PRIV_NETINET_SETHDROPTS);
 1652                                                 if (error)
 1653                                                         return (error);
 1654                                         }
 1655                                         OPTSET2292(IN6P_HOPOPTS);
 1656                                         break;
 1657                                 case IPV6_2292DSTOPTS:
 1658                                         if (td != NULL) {
 1659                                                 error = priv_check(td,
 1660                                                     PRIV_NETINET_SETHDROPTS);
 1661                                                 if (error)
 1662                                                         return (error);
 1663                                         }
 1664                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
 1665                                         break;
 1666                                 case IPV6_2292RTHDR:
 1667                                         OPTSET2292(IN6P_RTHDR);
 1668                                         break;
 1669                                 }
 1670                                 break;
 1671                         case IPV6_PKTINFO:
 1672                         case IPV6_HOPOPTS:
 1673                         case IPV6_RTHDR:
 1674                         case IPV6_DSTOPTS:
 1675                         case IPV6_RTHDRDSTOPTS:
 1676                         case IPV6_NEXTHOP:
 1677                         {
 1678                                 /* new advanced API (RFC3542) */
 1679                                 u_char *optbuf;
 1680                                 u_char optbuf_storage[MCLBYTES];
 1681                                 int optlen;
 1682                                 struct ip6_pktopts **optp;
 1683 
 1684                                 /* cannot mix with RFC2292 */
 1685                                 if (OPTBIT(IN6P_RFC2292)) {
 1686                                         error = EINVAL;
 1687                                         break;
 1688                                 }
 1689 
 1690                                 /*
 1691                                  * We only ensure valsize is not too large
 1692                                  * here.  Further validation will be done
 1693                                  * later.
 1694                                  */
 1695                                 error = sooptcopyin(sopt, optbuf_storage,
 1696                                     sizeof(optbuf_storage), 0);
 1697                                 if (error)
 1698                                         break;
 1699                                 optlen = sopt->sopt_valsize;
 1700                                 optbuf = optbuf_storage;
 1701                                 optp = &in6p->in6p_outputopts;
 1702                                 error = ip6_pcbopt(optname, optbuf, optlen,
 1703                                     optp, (td != NULL) ? td->td_ucred : NULL,
 1704                                     uproto);
 1705                                 break;
 1706                         }
 1707 #undef OPTSET
 1708 
 1709                         case IPV6_MULTICAST_IF:
 1710                         case IPV6_MULTICAST_HOPS:
 1711                         case IPV6_MULTICAST_LOOP:
 1712                         case IPV6_JOIN_GROUP:
 1713                         case IPV6_LEAVE_GROUP:
 1714                             {
 1715                                 if (sopt->sopt_valsize > MLEN) {
 1716                                         error = EMSGSIZE;
 1717                                         break;
 1718                                 }
 1719                                 /* XXX */
 1720                             }
 1721                             /* FALLTHROUGH */
 1722                             {
 1723                                 struct mbuf *m;
 1724 
 1725                                 if (sopt->sopt_valsize > MCLBYTES) {
 1726                                         error = EMSGSIZE;
 1727                                         break;
 1728                                 }
 1729                                 /* XXX */
 1730                                 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
 1731                                 if (m == 0) {
 1732                                         error = ENOBUFS;
 1733                                         break;
 1734                                 }
 1735                                 if (sopt->sopt_valsize > MLEN) {
 1736                                         MCLGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT);
 1737                                         if ((m->m_flags & M_EXT) == 0) {
 1738                                                 m_free(m);
 1739                                                 error = ENOBUFS;
 1740                                                 break;
 1741                                         }
 1742                                 }
 1743                                 m->m_len = sopt->sopt_valsize;
 1744                                 error = sooptcopyin(sopt, mtod(m, char *),
 1745                                                     m->m_len, m->m_len);
 1746                                 if (error) {
 1747                                         (void)m_free(m);
 1748                                         break;
 1749                                 }
 1750                                 error = ip6_setmoptions(sopt->sopt_name,
 1751                                                         &in6p->in6p_moptions,
 1752                                                         m);
 1753                                 (void)m_free(m);
 1754                             }
 1755                                 break;
 1756 
 1757                         case IPV6_PORTRANGE:
 1758                                 error = sooptcopyin(sopt, &optval,
 1759                                     sizeof optval, sizeof optval);
 1760                                 if (error)
 1761                                         break;
 1762 
 1763                                 switch (optval) {
 1764                                 case IPV6_PORTRANGE_DEFAULT:
 1765                                         in6p->inp_flags &= ~(INP_LOWPORT);
 1766                                         in6p->inp_flags &= ~(INP_HIGHPORT);
 1767                                         break;
 1768 
 1769                                 case IPV6_PORTRANGE_HIGH:
 1770                                         in6p->inp_flags &= ~(INP_LOWPORT);
 1771                                         in6p->inp_flags |= INP_HIGHPORT;
 1772                                         break;
 1773 
 1774                                 case IPV6_PORTRANGE_LOW:
 1775                                         in6p->inp_flags &= ~(INP_HIGHPORT);
 1776                                         in6p->inp_flags |= INP_LOWPORT;
 1777                                         break;
 1778 
 1779                                 default:
 1780                                         error = EINVAL;
 1781                                         break;
 1782                                 }
 1783                                 break;
 1784 
 1785 #ifdef IPSEC
 1786                         case IPV6_IPSEC_POLICY:
 1787                         {
 1788                                 caddr_t req;
 1789                                 struct mbuf *m;
 1790 
 1791                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
 1792                                         break;
 1793                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
 1794                                         break;
 1795                                 req = mtod(m, caddr_t);
 1796                                 error = ipsec6_set_policy(in6p, optname, req,
 1797                                     m->m_len, (sopt->sopt_td != NULL) ?
 1798                                     sopt->sopt_td->td_ucred : NULL);
 1799                                 m_freem(m);
 1800                                 break;
 1801                         }
 1802 #endif /* IPSEC */
 1803 
 1804                         default:
 1805                                 error = ENOPROTOOPT;
 1806                                 break;
 1807                         }
 1808                         break;
 1809 
 1810                 case SOPT_GET:
 1811                         switch (optname) {
 1812 
 1813                         case IPV6_2292PKTOPTIONS:
 1814 #ifdef IPV6_PKTOPTIONS
 1815                         case IPV6_PKTOPTIONS:
 1816 #endif
 1817                                 /*
 1818                                  * RFC3542 (effectively) deprecated the
 1819                                  * semantics of the 2292-style pktoptions.
 1820                                  * Since it was not reliable in nature (i.e.,
 1821                                  * applications had to expect the lack of some
 1822                                  * information after all), it would make sense
 1823                                  * to simplify this part by always returning
 1824                                  * empty data.
 1825                                  */
 1826                                 sopt->sopt_valsize = 0;
 1827                                 break;
 1828 
 1829                         case IPV6_RECVHOPOPTS:
 1830                         case IPV6_RECVDSTOPTS:
 1831                         case IPV6_RECVRTHDRDSTOPTS:
 1832                         case IPV6_UNICAST_HOPS:
 1833                         case IPV6_RECVPKTINFO:
 1834                         case IPV6_RECVHOPLIMIT:
 1835                         case IPV6_RECVRTHDR:
 1836                         case IPV6_RECVPATHMTU:
 1837 
 1838                         case IPV6_FAITH:
 1839                         case IPV6_V6ONLY:
 1840                         case IPV6_PORTRANGE:
 1841                         case IPV6_RECVTCLASS:
 1842                         case IPV6_AUTOFLOWLABEL:
 1843                                 switch (optname) {
 1844 
 1845                                 case IPV6_RECVHOPOPTS:
 1846                                         optval = OPTBIT(IN6P_HOPOPTS);
 1847                                         break;
 1848 
 1849                                 case IPV6_RECVDSTOPTS:
 1850                                         optval = OPTBIT(IN6P_DSTOPTS);
 1851                                         break;
 1852 
 1853                                 case IPV6_RECVRTHDRDSTOPTS:
 1854                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
 1855                                         break;
 1856 
 1857                                 case IPV6_UNICAST_HOPS:
 1858                                         optval = in6p->in6p_hops;
 1859                                         break;
 1860 
 1861                                 case IPV6_RECVPKTINFO:
 1862                                         optval = OPTBIT(IN6P_PKTINFO);
 1863                                         break;
 1864 
 1865                                 case IPV6_RECVHOPLIMIT:
 1866                                         optval = OPTBIT(IN6P_HOPLIMIT);
 1867                                         break;
 1868 
 1869                                 case IPV6_RECVRTHDR:
 1870                                         optval = OPTBIT(IN6P_RTHDR);
 1871                                         break;
 1872 
 1873                                 case IPV6_RECVPATHMTU:
 1874                                         optval = OPTBIT(IN6P_MTU);
 1875                                         break;
 1876 
 1877                                 case IPV6_FAITH:
 1878                                         optval = OPTBIT(INP_FAITH);
 1879                                         break;
 1880 
 1881                                 case IPV6_V6ONLY:
 1882                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
 1883                                         break;
 1884 
 1885                                 case IPV6_PORTRANGE:
 1886                                     {
 1887                                         int flags;
 1888                                         flags = in6p->inp_flags;
 1889                                         if (flags & INP_HIGHPORT)
 1890                                                 optval = IPV6_PORTRANGE_HIGH;
 1891                                         else if (flags & INP_LOWPORT)
 1892                                                 optval = IPV6_PORTRANGE_LOW;
 1893                                         else
 1894                                                 optval = 0;
 1895                                         break;
 1896                                     }
 1897                                 case IPV6_RECVTCLASS:
 1898                                         optval = OPTBIT(IN6P_TCLASS);
 1899                                         break;
 1900 
 1901                                 case IPV6_AUTOFLOWLABEL:
 1902                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
 1903                                         break;
 1904                                 }
 1905                                 if (error)
 1906                                         break;
 1907                                 error = sooptcopyout(sopt, &optval,
 1908                                         sizeof optval);
 1909                                 break;
 1910 
 1911                         case IPV6_PATHMTU:
 1912                         {
 1913                                 u_long pmtu = 0;
 1914                                 struct ip6_mtuinfo mtuinfo;
 1915                                 struct route_in6 sro;
 1916 
 1917                                 bzero(&sro, sizeof(sro));
 1918 
 1919                                 if (!(so->so_state & SS_ISCONNECTED))
 1920                                         return (ENOTCONN);
 1921                                 /*
 1922                                  * XXX: we dot not consider the case of source
 1923                                  * routing, or optional information to specify
 1924                                  * the outgoing interface.
 1925                                  */
 1926                                 error = ip6_getpmtu(&sro, NULL, NULL,
 1927                                     &in6p->in6p_faddr, &pmtu, NULL);
 1928                                 if (sro.ro_rt)
 1929                                         RTFREE(sro.ro_rt);
 1930                                 if (error)
 1931                                         break;
 1932                                 if (pmtu > IPV6_MAXPACKET)
 1933                                         pmtu = IPV6_MAXPACKET;
 1934 
 1935                                 bzero(&mtuinfo, sizeof(mtuinfo));
 1936                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
 1937                                 optdata = (void *)&mtuinfo;
 1938                                 optdatalen = sizeof(mtuinfo);
 1939                                 error = sooptcopyout(sopt, optdata,
 1940                                     optdatalen);
 1941                                 break;
 1942                         }
 1943 
 1944                         case IPV6_2292PKTINFO:
 1945                         case IPV6_2292HOPLIMIT:
 1946                         case IPV6_2292HOPOPTS:
 1947                         case IPV6_2292RTHDR:
 1948                         case IPV6_2292DSTOPTS:
 1949                                 switch (optname) {
 1950                                 case IPV6_2292PKTINFO:
 1951                                         optval = OPTBIT(IN6P_PKTINFO);
 1952                                         break;
 1953                                 case IPV6_2292HOPLIMIT:
 1954                                         optval = OPTBIT(IN6P_HOPLIMIT);
 1955                                         break;
 1956                                 case IPV6_2292HOPOPTS:
 1957                                         optval = OPTBIT(IN6P_HOPOPTS);
 1958                                         break;
 1959                                 case IPV6_2292RTHDR:
 1960                                         optval = OPTBIT(IN6P_RTHDR);
 1961                                         break;
 1962                                 case IPV6_2292DSTOPTS:
 1963                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
 1964                                         break;
 1965                                 }
 1966                                 error = sooptcopyout(sopt, &optval,
 1967                                     sizeof optval);
 1968                                 break;
 1969                         case IPV6_PKTINFO:
 1970                         case IPV6_HOPOPTS:
 1971                         case IPV6_RTHDR:
 1972                         case IPV6_DSTOPTS:
 1973                         case IPV6_RTHDRDSTOPTS:
 1974                         case IPV6_NEXTHOP:
 1975                         case IPV6_TCLASS:
 1976                         case IPV6_DONTFRAG:
 1977                         case IPV6_USE_MIN_MTU:
 1978                         case IPV6_PREFER_TEMPADDR:
 1979                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
 1980                                     optname, sopt);
 1981                                 break;
 1982 
 1983                         case IPV6_MULTICAST_IF:
 1984                         case IPV6_MULTICAST_HOPS:
 1985                         case IPV6_MULTICAST_LOOP:
 1986                         case IPV6_JOIN_GROUP:
 1987                         case IPV6_LEAVE_GROUP:
 1988                             {
 1989                                 struct mbuf *m;
 1990                                 error = ip6_getmoptions(sopt->sopt_name,
 1991                                     in6p->in6p_moptions, &m);
 1992                                 if (error == 0)
 1993                                         error = sooptcopyout(sopt,
 1994                                             mtod(m, char *), m->m_len);
 1995                                 m_freem(m);
 1996                             }
 1997                                 break;
 1998 
 1999 #ifdef IPSEC
 2000                         case IPV6_IPSEC_POLICY:
 2001                           {
 2002                                 caddr_t req = NULL;
 2003                                 size_t len = 0;
 2004                                 struct mbuf *m = NULL;
 2005                                 struct mbuf **mp = &m;
 2006                                 size_t ovalsize = sopt->sopt_valsize;
 2007                                 caddr_t oval = (caddr_t)sopt->sopt_val;
 2008 
 2009                                 error = soopt_getm(sopt, &m); /* XXX */
 2010                                 if (error != 0)
 2011                                         break;
 2012                                 error = soopt_mcopyin(sopt, m); /* XXX */
 2013                                 if (error != 0)
 2014                                         break;
 2015                                 sopt->sopt_valsize = ovalsize;
 2016                                 sopt->sopt_val = oval;
 2017                                 if (m) {
 2018                                         req = mtod(m, caddr_t);
 2019                                         len = m->m_len;
 2020                                 }
 2021                                 error = ipsec6_get_policy(in6p, req, len, mp);
 2022                                 if (error == 0)
 2023                                         error = soopt_mcopyout(sopt, m); /* XXX */
 2024                                 if (error == 0 && m)
 2025                                         m_freem(m);
 2026                                 break;
 2027                           }
 2028 #endif /* IPSEC */
 2029 
 2030                         default:
 2031                                 error = ENOPROTOOPT;
 2032                                 break;
 2033                         }
 2034                         break;
 2035                 }
 2036         } else {                /* level != IPPROTO_IPV6 */
 2037                 error = EINVAL;
 2038         }
 2039         return (error);
 2040 }
 2041 
 2042 int
 2043 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
 2044 {
 2045         int error = 0, optval, optlen;
 2046         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
 2047         struct inpcb *in6p = sotoinpcb(so);
 2048         int level, op, optname;
 2049 
 2050         level = sopt->sopt_level;
 2051         op = sopt->sopt_dir;
 2052         optname = sopt->sopt_name;
 2053         optlen = sopt->sopt_valsize;
 2054 
 2055         if (level != IPPROTO_IPV6) {
 2056                 return (EINVAL);
 2057         }
 2058 
 2059         switch (optname) {
 2060         case IPV6_CHECKSUM:
 2061                 /*
 2062                  * For ICMPv6 sockets, no modification allowed for checksum
 2063                  * offset, permit "no change" values to help existing apps.
 2064                  *
 2065                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
 2066                  * for an ICMPv6 socket will fail."
 2067                  * The current behavior does not meet RFC3542.
 2068                  */
 2069                 switch (op) {
 2070                 case SOPT_SET:
 2071                         if (optlen != sizeof(int)) {
 2072                                 error = EINVAL;
 2073                                 break;
 2074                         }
 2075                         error = sooptcopyin(sopt, &optval, sizeof(optval),
 2076                                             sizeof(optval));
 2077                         if (error)
 2078                                 break;
 2079                         if ((optval % 2) != 0) {
 2080                                 /* the API assumes even offset values */
 2081                                 error = EINVAL;
 2082                         } else if (so->so_proto->pr_protocol ==
 2083                             IPPROTO_ICMPV6) {
 2084                                 if (optval != icmp6off)
 2085                                         error = EINVAL;
 2086                         } else
 2087                                 in6p->in6p_cksum = optval;
 2088                         break;
 2089 
 2090                 case SOPT_GET:
 2091                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
 2092                                 optval = icmp6off;
 2093                         else
 2094                                 optval = in6p->in6p_cksum;
 2095 
 2096                         error = sooptcopyout(sopt, &optval, sizeof(optval));
 2097                         break;
 2098 
 2099                 default:
 2100                         error = EINVAL;
 2101                         break;
 2102                 }
 2103                 break;
 2104 
 2105         default:
 2106                 error = ENOPROTOOPT;
 2107                 break;
 2108         }
 2109 
 2110         return (error);
 2111 }
 2112 
 2113 /*
 2114  * Set up IP6 options in pcb for insertion in output packets or
 2115  * specifying behavior of outgoing packets.
 2116  */
 2117 static int
 2118 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
 2119     struct socket *so, struct sockopt *sopt)
 2120 {
 2121         struct ip6_pktopts *opt = *pktopt;
 2122         int error = 0;
 2123         struct thread *td = sopt->sopt_td;
 2124 
 2125         /* turn off any old options. */
 2126         if (opt) {
 2127 #ifdef DIAGNOSTIC
 2128                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
 2129                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
 2130                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
 2131                         printf("ip6_pcbopts: all specified options are cleared.\n");
 2132 #endif
 2133                 ip6_clearpktopts(opt, -1);
 2134         } else
 2135                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
 2136         *pktopt = NULL;
 2137 
 2138         if (!m || m->m_len == 0) {
 2139                 /*
 2140                  * Only turning off any previous options, regardless of
 2141                  * whether the opt is just created or given.
 2142                  */
 2143                 free(opt, M_IP6OPT);
 2144                 return (0);
 2145         }
 2146 
 2147         /*  set options specified by user. */
 2148         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
 2149             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
 2150                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
 2151                 free(opt, M_IP6OPT);
 2152                 return (error);
 2153         }
 2154         *pktopt = opt;
 2155         return (0);
 2156 }
 2157 
 2158 /*
 2159  * initialize ip6_pktopts.  beware that there are non-zero default values in
 2160  * the struct.
 2161  */
 2162 void
 2163 ip6_initpktopts(struct ip6_pktopts *opt)
 2164 {
 2165 
 2166         bzero(opt, sizeof(*opt));
 2167         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
 2168         opt->ip6po_tclass = -1; /* -1 means default traffic class */
 2169         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
 2170         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
 2171 }
 2172 
 2173 static int
 2174 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
 2175     struct ucred *cred, int uproto)
 2176 {
 2177         struct ip6_pktopts *opt;
 2178 
 2179         if (*pktopt == NULL) {
 2180                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
 2181                     M_WAITOK);
 2182                 ip6_initpktopts(*pktopt);
 2183         }
 2184         opt = *pktopt;
 2185 
 2186         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
 2187 }
 2188 
 2189 static int
 2190 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
 2191 {
 2192         void *optdata = NULL;
 2193         int optdatalen = 0;
 2194         struct ip6_ext *ip6e;
 2195         int error = 0;
 2196         struct in6_pktinfo null_pktinfo;
 2197         int deftclass = 0, on;
 2198         int defminmtu = IP6PO_MINMTU_MCASTONLY;
 2199         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
 2200 
 2201         switch (optname) {
 2202         case IPV6_PKTINFO:
 2203                 if (pktopt && pktopt->ip6po_pktinfo)
 2204                         optdata = (void *)pktopt->ip6po_pktinfo;
 2205                 else {
 2206                         /* XXX: we don't have to do this every time... */
 2207                         bzero(&null_pktinfo, sizeof(null_pktinfo));
 2208                         optdata = (void *)&null_pktinfo;
 2209                 }
 2210                 optdatalen = sizeof(struct in6_pktinfo);
 2211                 break;
 2212         case IPV6_TCLASS:
 2213                 if (pktopt && pktopt->ip6po_tclass >= 0)
 2214                         optdata = (void *)&pktopt->ip6po_tclass;
 2215                 else
 2216                         optdata = (void *)&deftclass;
 2217                 optdatalen = sizeof(int);
 2218                 break;
 2219         case IPV6_HOPOPTS:
 2220                 if (pktopt && pktopt->ip6po_hbh) {
 2221                         optdata = (void *)pktopt->ip6po_hbh;
 2222                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
 2223                         optdatalen = (ip6e->ip6e_len + 1) << 3;
 2224                 }
 2225                 break;
 2226         case IPV6_RTHDR:
 2227                 if (pktopt && pktopt->ip6po_rthdr) {
 2228                         optdata = (void *)pktopt->ip6po_rthdr;
 2229                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
 2230                         optdatalen = (ip6e->ip6e_len + 1) << 3;
 2231                 }
 2232                 break;
 2233         case IPV6_RTHDRDSTOPTS:
 2234                 if (pktopt && pktopt->ip6po_dest1) {
 2235                         optdata = (void *)pktopt->ip6po_dest1;
 2236                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
 2237                         optdatalen = (ip6e->ip6e_len + 1) << 3;
 2238                 }
 2239                 break;
 2240         case IPV6_DSTOPTS:
 2241                 if (pktopt && pktopt->ip6po_dest2) {
 2242                         optdata = (void *)pktopt->ip6po_dest2;
 2243                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
 2244                         optdatalen = (ip6e->ip6e_len + 1) << 3;
 2245                 }
 2246                 break;
 2247         case IPV6_NEXTHOP:
 2248                 if (pktopt && pktopt->ip6po_nexthop) {
 2249                         optdata = (void *)pktopt->ip6po_nexthop;
 2250                         optdatalen = pktopt->ip6po_nexthop->sa_len;
 2251                 }
 2252                 break;
 2253         case IPV6_USE_MIN_MTU:
 2254                 if (pktopt)
 2255                         optdata = (void *)&pktopt->ip6po_minmtu;
 2256                 else
 2257                         optdata = (void *)&defminmtu;
 2258                 optdatalen = sizeof(int);
 2259                 break;
 2260         case IPV6_DONTFRAG:
 2261                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
 2262                         on = 1;
 2263                 else
 2264                         on = 0;
 2265                 optdata = (void *)&on;
 2266                 optdatalen = sizeof(on);
 2267                 break;
 2268         case IPV6_PREFER_TEMPADDR:
 2269                 if (pktopt)
 2270                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
 2271                 else
 2272                         optdata = (void *)&defpreftemp;
 2273                 optdatalen = sizeof(int);
 2274                 break;
 2275         default:                /* should not happen */
 2276 #ifdef DIAGNOSTIC
 2277                 panic("ip6_getpcbopt: unexpected option\n");
 2278 #endif
 2279                 return (ENOPROTOOPT);
 2280         }
 2281 
 2282         error = sooptcopyout(sopt, optdata, optdatalen);
 2283 
 2284         return (error);
 2285 }
 2286 
 2287 void
 2288 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
 2289 {
 2290         if (pktopt == NULL)
 2291                 return;
 2292 
 2293         if (optname == -1 || optname == IPV6_PKTINFO) {
 2294                 if (pktopt->ip6po_pktinfo)
 2295                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
 2296                 pktopt->ip6po_pktinfo = NULL;
 2297         }
 2298         if (optname == -1 || optname == IPV6_HOPLIMIT)
 2299                 pktopt->ip6po_hlim = -1;
 2300         if (optname == -1 || optname == IPV6_TCLASS)
 2301                 pktopt->ip6po_tclass = -1;
 2302         if (optname == -1 || optname == IPV6_NEXTHOP) {
 2303                 if (pktopt->ip6po_nextroute.ro_rt) {
 2304                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
 2305                         pktopt->ip6po_nextroute.ro_rt = NULL;
 2306                 }
 2307                 if (pktopt->ip6po_nexthop)
 2308                         free(pktopt->ip6po_nexthop, M_IP6OPT);
 2309                 pktopt->ip6po_nexthop = NULL;
 2310         }
 2311         if (optname == -1 || optname == IPV6_HOPOPTS) {
 2312                 if (pktopt->ip6po_hbh)
 2313                         free(pktopt->ip6po_hbh, M_IP6OPT);
 2314                 pktopt->ip6po_hbh = NULL;
 2315         }
 2316         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
 2317                 if (pktopt->ip6po_dest1)
 2318                         free(pktopt->ip6po_dest1, M_IP6OPT);
 2319                 pktopt->ip6po_dest1 = NULL;
 2320         }
 2321         if (optname == -1 || optname == IPV6_RTHDR) {
 2322                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
 2323                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
 2324                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
 2325                 if (pktopt->ip6po_route.ro_rt) {
 2326                         RTFREE(pktopt->ip6po_route.ro_rt);
 2327                         pktopt->ip6po_route.ro_rt = NULL;
 2328                 }
 2329         }
 2330         if (optname == -1 || optname == IPV6_DSTOPTS) {
 2331                 if (pktopt->ip6po_dest2)
 2332                         free(pktopt->ip6po_dest2, M_IP6OPT);
 2333                 pktopt->ip6po_dest2 = NULL;
 2334         }
 2335 }
 2336 
 2337 #define PKTOPT_EXTHDRCPY(type) \
 2338 do {\
 2339         if (src->type) {\
 2340                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
 2341                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
 2342                 if (dst->type == NULL && canwait == M_NOWAIT)\
 2343                         goto bad;\
 2344                 bcopy(src->type, dst->type, hlen);\
 2345         }\
 2346 } while (/*CONSTCOND*/ 0)
 2347 
 2348 static int
 2349 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
 2350 {
 2351         if (dst == NULL || src == NULL)  {
 2352                 printf("ip6_clearpktopts: invalid argument\n");
 2353                 return (EINVAL);
 2354         }
 2355 
 2356         dst->ip6po_hlim = src->ip6po_hlim;
 2357         dst->ip6po_tclass = src->ip6po_tclass;
 2358         dst->ip6po_flags = src->ip6po_flags;
 2359         if (src->ip6po_pktinfo) {
 2360                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
 2361                     M_IP6OPT, canwait);
 2362                 if (dst->ip6po_pktinfo == NULL)
 2363                         goto bad;
 2364                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
 2365         }
 2366         if (src->ip6po_nexthop) {
 2367                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
 2368                     M_IP6OPT, canwait);
 2369                 if (dst->ip6po_nexthop == NULL)
 2370                         goto bad;
 2371                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
 2372                     src->ip6po_nexthop->sa_len);
 2373         }
 2374         PKTOPT_EXTHDRCPY(ip6po_hbh);
 2375         PKTOPT_EXTHDRCPY(ip6po_dest1);
 2376         PKTOPT_EXTHDRCPY(ip6po_dest2);
 2377         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
 2378         return (0);
 2379 
 2380   bad:
 2381         ip6_clearpktopts(dst, -1);
 2382         return (ENOBUFS);
 2383 }
 2384 #undef PKTOPT_EXTHDRCPY
 2385 
 2386 struct ip6_pktopts *
 2387 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
 2388 {
 2389         int error;
 2390         struct ip6_pktopts *dst;
 2391 
 2392         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
 2393         if (dst == NULL)
 2394                 return (NULL);
 2395         ip6_initpktopts(dst);
 2396 
 2397         if ((error = copypktopts(dst, src, canwait)) != 0) {
 2398                 free(dst, M_IP6OPT);
 2399                 return (NULL);
 2400         }
 2401 
 2402         return (dst);
 2403 }
 2404 
 2405 void
 2406 ip6_freepcbopts(struct ip6_pktopts *pktopt)
 2407 {
 2408         if (pktopt == NULL)
 2409                 return;
 2410 
 2411         ip6_clearpktopts(pktopt, -1);
 2412 
 2413         free(pktopt, M_IP6OPT);
 2414 }
 2415 
 2416 /*
 2417  * Set the IP6 multicast options in response to user setsockopt().
 2418  */
 2419 static int
 2420 ip6_setmoptions(int optname, struct ip6_moptions **im6op, struct mbuf *m)
 2421 {
 2422         int error = 0;
 2423         u_int loop, ifindex;
 2424         struct ipv6_mreq *mreq;
 2425         struct ifnet *ifp;
 2426         struct ip6_moptions *im6o = *im6op;
 2427         struct route_in6 ro;
 2428         struct in6_multi_mship *imm;
 2429 
 2430         if (im6o == NULL) {
 2431                 /*
 2432                  * No multicast option buffer attached to the pcb;
 2433                  * allocate one and initialize to default values.
 2434                  */
 2435                 im6o = (struct ip6_moptions *)
 2436                         malloc(sizeof(*im6o), M_IP6MOPTS, M_WAITOK);
 2437 
 2438                 if (im6o == NULL)
 2439                         return (ENOBUFS);
 2440                 *im6op = im6o;
 2441                 im6o->im6o_multicast_ifp = NULL;
 2442                 im6o->im6o_multicast_hlim = ip6_defmcasthlim;
 2443                 im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
 2444                 LIST_INIT(&im6o->im6o_memberships);
 2445         }
 2446 
 2447         switch (optname) {
 2448 
 2449         case IPV6_MULTICAST_IF:
 2450                 /*
 2451                  * Select the interface for outgoing multicast packets.
 2452                  */
 2453                 if (m == NULL || m->m_len != sizeof(u_int)) {
 2454                         error = EINVAL;
 2455                         break;
 2456                 }
 2457                 bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
 2458                 if (ifindex < 0 || if_index < ifindex) {
 2459                         error = ENXIO;  /* XXX EINVAL? */
 2460                         break;
 2461                 }
 2462                 ifp = ifnet_byindex(ifindex);
 2463                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
 2464                         error = EADDRNOTAVAIL;
 2465                         break;
 2466                 }
 2467                 im6o->im6o_multicast_ifp = ifp;
 2468                 break;
 2469 
 2470         case IPV6_MULTICAST_HOPS:
 2471             {
 2472                 /*
 2473                  * Set the IP6 hoplimit for outgoing multicast packets.
 2474                  */
 2475                 int optval;
 2476                 if (m == NULL || m->m_len != sizeof(int)) {
 2477                         error = EINVAL;
 2478                         break;
 2479                 }
 2480                 bcopy(mtod(m, u_int *), &optval, sizeof(optval));
 2481                 if (optval < -1 || optval >= 256)
 2482                         error = EINVAL;
 2483                 else if (optval == -1)
 2484                         im6o->im6o_multicast_hlim = ip6_defmcasthlim;
 2485                 else
 2486                         im6o->im6o_multicast_hlim = optval;
 2487                 break;
 2488             }
 2489 
 2490         case IPV6_MULTICAST_LOOP:
 2491                 /*
 2492                  * Set the loopback flag for outgoing multicast packets.
 2493                  * Must be zero or one.
 2494                  */
 2495                 if (m == NULL || m->m_len != sizeof(u_int)) {
 2496                         error = EINVAL;
 2497                         break;
 2498                 }
 2499                 bcopy(mtod(m, u_int *), &loop, sizeof(loop));
 2500                 if (loop > 1) {
 2501                         error = EINVAL;
 2502                         break;
 2503                 }
 2504                 im6o->im6o_multicast_loop = loop;
 2505                 break;
 2506 
 2507         case IPV6_JOIN_GROUP:
 2508                 /*
 2509                  * Add a multicast group membership.
 2510                  * Group must be a valid IP6 multicast address.
 2511                  */
 2512                 if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
 2513                         error = EINVAL;
 2514                         break;
 2515                 }
 2516                 mreq = mtod(m, struct ipv6_mreq *);
 2517 
 2518                 if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
 2519                         /*
 2520                          * We use the unspecified address to specify to accept
 2521                          * all multicast addresses. Only super user is allowed
 2522                          * to do this.
 2523                          */
 2524                         /* XXX-BZ might need a better PRIV_NETINET_x for this */
 2525                         error = priv_check(curthread, PRIV_NETINET_MROUTE);
 2526                         if (error)
 2527                                 break;
 2528                 } else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
 2529                         error = EINVAL;
 2530                         break;
 2531                 }
 2532 
 2533                 /*
 2534                  * If no interface was explicitly specified, choose an
 2535                  * appropriate one according to the given multicast address.
 2536                  */
 2537                 if (mreq->ipv6mr_interface == 0) {
 2538                         struct sockaddr_in6 *dst;
 2539 
 2540                         /*
 2541                          * Look up the routing table for the
 2542                          * address, and choose the outgoing interface.
 2543                          *   XXX: is it a good approach?
 2544                          */
 2545                         ro.ro_rt = NULL;
 2546                         dst = (struct sockaddr_in6 *)&ro.ro_dst;
 2547                         bzero(dst, sizeof(*dst));
 2548                         dst->sin6_family = AF_INET6;
 2549                         dst->sin6_len = sizeof(*dst);
 2550                         dst->sin6_addr = mreq->ipv6mr_multiaddr;
 2551                         rtalloc((struct route *)&ro);
 2552                         if (ro.ro_rt == NULL) {
 2553                                 error = EADDRNOTAVAIL;
 2554                                 break;
 2555                         }
 2556                         ifp = ro.ro_rt->rt_ifp;
 2557                         RTFREE(ro.ro_rt);
 2558                 } else {
 2559                         /*
 2560                          * If the interface is specified, validate it.
 2561                          */
 2562                         if (mreq->ipv6mr_interface < 0 ||
 2563                             if_index < mreq->ipv6mr_interface) {
 2564                                 error = ENXIO;  /* XXX EINVAL? */
 2565                                 break;
 2566                         }
 2567                         ifp = ifnet_byindex(mreq->ipv6mr_interface);
 2568                         if (!ifp) {
 2569                                 error = ENXIO;  /* XXX EINVAL? */
 2570                                 break;
 2571                         }
 2572                 }
 2573 
 2574                 /*
 2575                  * See if we found an interface, and confirm that it
 2576                  * supports multicast
 2577                  */
 2578                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
 2579                         error = EADDRNOTAVAIL;
 2580                         break;
 2581                 }
 2582 
 2583                 if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
 2584                         error = EADDRNOTAVAIL; /* XXX: should not happen */
 2585                         break;
 2586                 }
 2587 
 2588                 /*
 2589                  * See if the membership already exists.
 2590                  */
 2591                 for (imm = im6o->im6o_memberships.lh_first;
 2592                      imm != NULL; imm = imm->i6mm_chain.le_next)
 2593                         if (imm->i6mm_maddr->in6m_ifp == ifp &&
 2594                             IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
 2595                                                &mreq->ipv6mr_multiaddr))
 2596                                 break;
 2597                 if (imm != NULL) {
 2598                         error = EADDRINUSE;
 2599                         break;
 2600                 }
 2601                 /*
 2602                  * Everything looks good; add a new record to the multicast
 2603                  * address list for the given interface.
 2604                  */
 2605                 imm = in6_joingroup(ifp, &mreq->ipv6mr_multiaddr,  &error, 0);
 2606                 if (imm == NULL)
 2607                         break;
 2608                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
 2609                 break;
 2610 
 2611         case IPV6_LEAVE_GROUP:
 2612                 /*
 2613                  * Drop a multicast group membership.
 2614                  * Group must be a valid IP6 multicast address.
 2615                  */
 2616                 if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
 2617                         error = EINVAL;
 2618                         break;
 2619                 }
 2620                 mreq = mtod(m, struct ipv6_mreq *);
 2621 
 2622                 /*
 2623                  * If an interface address was specified, get a pointer
 2624                  * to its ifnet structure.
 2625                  */
 2626                 if (mreq->ipv6mr_interface < 0 ||
 2627                     if_index < mreq->ipv6mr_interface) {
 2628                         error = ENXIO;  /* XXX EINVAL? */
 2629                         break;
 2630                 }
 2631                 if (mreq->ipv6mr_interface == 0)
 2632                         ifp = NULL;
 2633                 else
 2634                         ifp = ifnet_byindex(mreq->ipv6mr_interface);
 2635 
 2636                 /* Fill in the scope zone ID */
 2637                 if (ifp) {
 2638                         if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
 2639                                 /* XXX: should not happen */
 2640                                 error = EADDRNOTAVAIL;
 2641                                 break;
 2642                         }
 2643                 } else if (mreq->ipv6mr_interface != 0) {
 2644                         /*
 2645                          * This case happens when the (positive) index is in
 2646                          * the valid range, but the corresponding interface has
 2647                          * been detached dynamically (XXX).
 2648                          */
 2649                         error = EADDRNOTAVAIL;
 2650                         break;
 2651                 } else {        /* ipv6mr_interface == 0 */
 2652                         struct sockaddr_in6 sa6_mc;
 2653 
 2654                         /*
 2655                          * The API spec says as follows:
 2656                          *  If the interface index is specified as 0, the
 2657                          *  system may choose a multicast group membership to
 2658                          *  drop by matching the multicast address only.
 2659                          * On the other hand, we cannot disambiguate the scope
 2660                          * zone unless an interface is provided.  Thus, we
 2661                          * check if there's ambiguity with the default scope
 2662                          * zone as the last resort.
 2663                          */
 2664                         bzero(&sa6_mc, sizeof(sa6_mc));
 2665                         sa6_mc.sin6_family = AF_INET6;
 2666                         sa6_mc.sin6_len = sizeof(sa6_mc);
 2667                         sa6_mc.sin6_addr = mreq->ipv6mr_multiaddr;
 2668                         error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
 2669                         if (error != 0)
 2670                                 break;
 2671                         mreq->ipv6mr_multiaddr = sa6_mc.sin6_addr;
 2672                 }
 2673 
 2674                 /*
 2675                  * Find the membership in the membership list.
 2676                  */
 2677                 for (imm = im6o->im6o_memberships.lh_first;
 2678                      imm != NULL; imm = imm->i6mm_chain.le_next) {
 2679                         if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
 2680                             IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
 2681                             &mreq->ipv6mr_multiaddr))
 2682                                 break;
 2683                 }
 2684                 if (imm == NULL) {
 2685                         /* Unable to resolve interface */
 2686                         error = EADDRNOTAVAIL;
 2687                         break;
 2688                 }
 2689                 /*
 2690                  * Give up the multicast address record to which the
 2691                  * membership points.
 2692                  */
 2693                 LIST_REMOVE(imm, i6mm_chain);
 2694                 in6_delmulti(imm->i6mm_maddr);
 2695                 free(imm, M_IP6MADDR);
 2696                 break;
 2697 
 2698         default:
 2699                 error = EOPNOTSUPP;
 2700                 break;
 2701         }
 2702 
 2703         /*
 2704          * If all options have default values, no need to keep the mbuf.
 2705          */
 2706         if (im6o->im6o_multicast_ifp == NULL &&
 2707             im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
 2708             im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
 2709             im6o->im6o_memberships.lh_first == NULL) {
 2710                 free(*im6op, M_IP6MOPTS);
 2711                 *im6op = NULL;
 2712         }
 2713 
 2714         return (error);
 2715 }
 2716 
 2717 /*
 2718  * Return the IP6 multicast options in response to user getsockopt().
 2719  */
 2720 static int
 2721 ip6_getmoptions(int optname, struct ip6_moptions *im6o, struct mbuf **mp)
 2722 {
 2723         u_int *hlim, *loop, *ifindex;
 2724 
 2725         *mp = m_get(M_TRYWAIT, MT_HEADER);              /* XXX */
 2726 
 2727         switch (optname) {
 2728 
 2729         case IPV6_MULTICAST_IF:
 2730                 ifindex = mtod(*mp, u_int *);
 2731                 (*mp)->m_len = sizeof(u_int);
 2732                 if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
 2733                         *ifindex = 0;
 2734                 else
 2735                         *ifindex = im6o->im6o_multicast_ifp->if_index;
 2736                 return (0);
 2737 
 2738         case IPV6_MULTICAST_HOPS:
 2739                 hlim = mtod(*mp, u_int *);
 2740                 (*mp)->m_len = sizeof(u_int);
 2741                 if (im6o == NULL)
 2742                         *hlim = ip6_defmcasthlim;
 2743                 else
 2744                         *hlim = im6o->im6o_multicast_hlim;
 2745                 return (0);
 2746 
 2747         case IPV6_MULTICAST_LOOP:
 2748                 loop = mtod(*mp, u_int *);
 2749                 (*mp)->m_len = sizeof(u_int);
 2750                 if (im6o == NULL)
 2751                         *loop = ip6_defmcasthlim;
 2752                 else
 2753                         *loop = im6o->im6o_multicast_loop;
 2754                 return (0);
 2755 
 2756         default:
 2757                 return (EOPNOTSUPP);
 2758         }
 2759 }
 2760 
 2761 /*
 2762  * Discard the IP6 multicast options.
 2763  */
 2764 void
 2765 ip6_freemoptions(struct ip6_moptions *im6o)
 2766 {
 2767         struct in6_multi_mship *imm;
 2768 
 2769         if (im6o == NULL)
 2770                 return;
 2771 
 2772         while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
 2773                 LIST_REMOVE(imm, i6mm_chain);
 2774                 if (imm->i6mm_maddr)
 2775                         in6_delmulti(imm->i6mm_maddr);
 2776                 free(imm, M_IP6MADDR);
 2777         }
 2778         free(im6o, M_IP6MOPTS);
 2779 }
 2780 
 2781 /*
 2782  * Set IPv6 outgoing packet options based on advanced API.
 2783  */
 2784 int
 2785 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
 2786     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
 2787 {
 2788         struct cmsghdr *cm = 0;
 2789 
 2790         if (control == NULL || opt == NULL)
 2791                 return (EINVAL);
 2792 
 2793         ip6_initpktopts(opt);
 2794         if (stickyopt) {
 2795                 int error;
 2796 
 2797                 /*
 2798                  * If stickyopt is provided, make a local copy of the options
 2799                  * for this particular packet, then override them by ancillary
 2800                  * objects.
 2801                  * XXX: copypktopts() does not copy the cached route to a next
 2802                  * hop (if any).  This is not very good in terms of efficiency,
 2803                  * but we can allow this since this option should be rarely
 2804                  * used.
 2805                  */
 2806                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
 2807                         return (error);
 2808         }
 2809 
 2810         /*
 2811          * XXX: Currently, we assume all the optional information is stored
 2812          * in a single mbuf.
 2813          */
 2814         if (control->m_next)
 2815                 return (EINVAL);
 2816 
 2817         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
 2818             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 2819                 int error;
 2820 
 2821                 if (control->m_len < CMSG_LEN(0))
 2822                         return (EINVAL);
 2823 
 2824                 cm = mtod(control, struct cmsghdr *);
 2825                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
 2826                         return (EINVAL);
 2827                 if (cm->cmsg_level != IPPROTO_IPV6)
 2828                         continue;
 2829 
 2830                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
 2831                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
 2832                 if (error)
 2833                         return (error);
 2834         }
 2835 
 2836         return (0);
 2837 }
 2838 
 2839 /*
 2840  * Set a particular packet option, as a sticky option or an ancillary data
 2841  * item.  "len" can be 0 only when it's a sticky option.
 2842  * We have 4 cases of combination of "sticky" and "cmsg":
 2843  * "sticky=0, cmsg=0": impossible
 2844  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
 2845  * "sticky=1, cmsg=0": RFC3542 socket option
 2846  * "sticky=1, cmsg=1": RFC2292 socket option
 2847  */
 2848 static int
 2849 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
 2850     struct ucred *cred, int sticky, int cmsg, int uproto)
 2851 {
 2852         int minmtupolicy, preftemp;
 2853         int error;
 2854 
 2855         if (!sticky && !cmsg) {
 2856 #ifdef DIAGNOSTIC
 2857                 printf("ip6_setpktopt: impossible case\n");
 2858 #endif
 2859                 return (EINVAL);
 2860         }
 2861 
 2862         /*
 2863          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
 2864          * not be specified in the context of RFC3542.  Conversely,
 2865          * RFC3542 types should not be specified in the context of RFC2292.
 2866          */
 2867         if (!cmsg) {
 2868                 switch (optname) {
 2869                 case IPV6_2292PKTINFO:
 2870                 case IPV6_2292HOPLIMIT:
 2871                 case IPV6_2292NEXTHOP:
 2872                 case IPV6_2292HOPOPTS:
 2873                 case IPV6_2292DSTOPTS:
 2874                 case IPV6_2292RTHDR:
 2875                 case IPV6_2292PKTOPTIONS:
 2876                         return (ENOPROTOOPT);
 2877                 }
 2878         }
 2879         if (sticky && cmsg) {
 2880                 switch (optname) {
 2881                 case IPV6_PKTINFO:
 2882                 case IPV6_HOPLIMIT:
 2883                 case IPV6_NEXTHOP:
 2884                 case IPV6_HOPOPTS:
 2885                 case IPV6_DSTOPTS:
 2886                 case IPV6_RTHDRDSTOPTS:
 2887                 case IPV6_RTHDR:
 2888                 case IPV6_USE_MIN_MTU:
 2889                 case IPV6_DONTFRAG:
 2890                 case IPV6_TCLASS:
 2891                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
 2892                         return (ENOPROTOOPT);
 2893                 }
 2894         }
 2895 
 2896         switch (optname) {
 2897         case IPV6_2292PKTINFO:
 2898         case IPV6_PKTINFO:
 2899         {
 2900                 struct ifnet *ifp = NULL;
 2901                 struct in6_pktinfo *pktinfo;
 2902 
 2903                 if (len != sizeof(struct in6_pktinfo))
 2904                         return (EINVAL);
 2905 
 2906                 pktinfo = (struct in6_pktinfo *)buf;
 2907 
 2908                 /*
 2909                  * An application can clear any sticky IPV6_PKTINFO option by
 2910                  * doing a "regular" setsockopt with ipi6_addr being
 2911                  * in6addr_any and ipi6_ifindex being zero.
 2912                  * [RFC 3542, Section 6]
 2913                  */
 2914                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
 2915                     pktinfo->ipi6_ifindex == 0 &&
 2916                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
 2917                         ip6_clearpktopts(opt, optname);
 2918                         break;
 2919                 }
 2920 
 2921                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
 2922                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
 2923                         return (EINVAL);
 2924                 }
 2925 
 2926                 /* validate the interface index if specified. */
 2927                 if (pktinfo->ipi6_ifindex > if_index ||
 2928                     pktinfo->ipi6_ifindex < 0) {
 2929                          return (ENXIO);
 2930                 }
 2931                 if (pktinfo->ipi6_ifindex) {
 2932                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
 2933                         if (ifp == NULL)
 2934                                 return (ENXIO);
 2935                 }
 2936 
 2937                 /*
 2938                  * We store the address anyway, and let in6_selectsrc()
 2939                  * validate the specified address.  This is because ipi6_addr
 2940                  * may not have enough information about its scope zone, and
 2941                  * we may need additional information (such as outgoing
 2942                  * interface or the scope zone of a destination address) to
 2943                  * disambiguate the scope.
 2944                  * XXX: the delay of the validation may confuse the
 2945                  * application when it is used as a sticky option.
 2946                  */
 2947                 if (opt->ip6po_pktinfo == NULL) {
 2948                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
 2949                             M_IP6OPT, M_NOWAIT);
 2950                         if (opt->ip6po_pktinfo == NULL)
 2951                                 return (ENOBUFS);
 2952                 }
 2953                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
 2954                 break;
 2955         }
 2956 
 2957         case IPV6_2292HOPLIMIT:
 2958         case IPV6_HOPLIMIT:
 2959         {
 2960                 int *hlimp;
 2961 
 2962                 /*
 2963                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
 2964                  * to simplify the ordering among hoplimit options.
 2965                  */
 2966                 if (optname == IPV6_HOPLIMIT && sticky)
 2967                         return (ENOPROTOOPT);
 2968 
 2969                 if (len != sizeof(int))
 2970                         return (EINVAL);
 2971                 hlimp = (int *)buf;
 2972                 if (*hlimp < -1 || *hlimp > 255)
 2973                         return (EINVAL);
 2974 
 2975                 opt->ip6po_hlim = *hlimp;
 2976                 break;
 2977         }
 2978 
 2979         case IPV6_TCLASS:
 2980         {
 2981                 int tclass;
 2982 
 2983                 if (len != sizeof(int))
 2984                         return (EINVAL);
 2985                 tclass = *(int *)buf;
 2986                 if (tclass < -1 || tclass > 255)
 2987                         return (EINVAL);
 2988 
 2989                 opt->ip6po_tclass = tclass;
 2990                 break;
 2991         }
 2992 
 2993         case IPV6_2292NEXTHOP:
 2994         case IPV6_NEXTHOP:
 2995                 if (cred != NULL) {
 2996                         error = priv_check_cred(cred,
 2997                             PRIV_NETINET_SETHDROPTS, 0);
 2998                         if (error)
 2999                                 return (error);
 3000                 }
 3001 
 3002                 if (len == 0) { /* just remove the option */
 3003                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
 3004                         break;
 3005                 }
 3006 
 3007                 /* check if cmsg_len is large enough for sa_len */
 3008                 if (len < sizeof(struct sockaddr) || len < *buf)
 3009                         return (EINVAL);
 3010 
 3011                 switch (((struct sockaddr *)buf)->sa_family) {
 3012                 case AF_INET6:
 3013                 {
 3014                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
 3015                         int error;
 3016 
 3017                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
 3018                                 return (EINVAL);
 3019 
 3020                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
 3021                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
 3022                                 return (EINVAL);
 3023                         }
 3024                         if ((error = sa6_embedscope(sa6, ip6_use_defzone))
 3025                             != 0) {
 3026                                 return (error);
 3027                         }
 3028                         break;
 3029                 }
 3030                 case AF_LINK:   /* should eventually be supported */
 3031                 default:
 3032                         return (EAFNOSUPPORT);
 3033                 }
 3034 
 3035                 /* turn off the previous option, then set the new option. */
 3036                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
 3037                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
 3038                 if (opt->ip6po_nexthop == NULL)
 3039                         return (ENOBUFS);
 3040                 bcopy(buf, opt->ip6po_nexthop, *buf);
 3041                 break;
 3042 
 3043         case IPV6_2292HOPOPTS:
 3044         case IPV6_HOPOPTS:
 3045         {
 3046                 struct ip6_hbh *hbh;
 3047                 int hbhlen;
 3048 
 3049                 /*
 3050                  * XXX: We don't allow a non-privileged user to set ANY HbH
 3051                  * options, since per-option restriction has too much
 3052                  * overhead.
 3053                  */
 3054                 if (cred != NULL) {
 3055                         error = priv_check_cred(cred,
 3056                             PRIV_NETINET_SETHDROPTS, 0);
 3057                         if (error)
 3058                                 return (error);
 3059                 }
 3060 
 3061                 if (len == 0) {
 3062                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
 3063                         break;  /* just remove the option */
 3064                 }
 3065 
 3066                 /* message length validation */
 3067                 if (len < sizeof(struct ip6_hbh))
 3068                         return (EINVAL);
 3069                 hbh = (struct ip6_hbh *)buf;
 3070                 hbhlen = (hbh->ip6h_len + 1) << 3;
 3071                 if (len != hbhlen)
 3072                         return (EINVAL);
 3073 
 3074                 /* turn off the previous option, then set the new option. */
 3075                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
 3076                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
 3077                 if (opt->ip6po_hbh == NULL)
 3078                         return (ENOBUFS);
 3079                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
 3080 
 3081                 break;
 3082         }
 3083 
 3084         case IPV6_2292DSTOPTS:
 3085         case IPV6_DSTOPTS:
 3086         case IPV6_RTHDRDSTOPTS:
 3087         {
 3088                 struct ip6_dest *dest, **newdest = NULL;
 3089                 int destlen;
 3090 
 3091                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
 3092                         error = priv_check_cred(cred,
 3093                             PRIV_NETINET_SETHDROPTS, 0);
 3094                         if (error)
 3095                                 return (error);
 3096                 }
 3097 
 3098                 if (len == 0) {
 3099                         ip6_clearpktopts(opt, optname);
 3100                         break;  /* just remove the option */
 3101                 }
 3102 
 3103                 /* message length validation */
 3104                 if (len < sizeof(struct ip6_dest))
 3105                         return (EINVAL);
 3106                 dest = (struct ip6_dest *)buf;
 3107                 destlen = (dest->ip6d_len + 1) << 3;
 3108                 if (len != destlen)
 3109                         return (EINVAL);
 3110 
 3111                 /*
 3112                  * Determine the position that the destination options header
 3113                  * should be inserted; before or after the routing header.
 3114                  */
 3115                 switch (optname) {
 3116                 case IPV6_2292DSTOPTS:
 3117                         /*
 3118                          * The old advacned API is ambiguous on this point.
 3119                          * Our approach is to determine the position based
 3120                          * according to the existence of a routing header.
 3121                          * Note, however, that this depends on the order of the
 3122                          * extension headers in the ancillary data; the 1st
 3123                          * part of the destination options header must appear
 3124                          * before the routing header in the ancillary data,
 3125                          * too.
 3126                          * RFC3542 solved the ambiguity by introducing
 3127                          * separate ancillary data or option types.
 3128                          */
 3129                         if (opt->ip6po_rthdr == NULL)
 3130                                 newdest = &opt->ip6po_dest1;
 3131                         else
 3132                                 newdest = &opt->ip6po_dest2;
 3133                         break;
 3134                 case IPV6_RTHDRDSTOPTS:
 3135                         newdest = &opt->ip6po_dest1;
 3136                         break;
 3137                 case IPV6_DSTOPTS:
 3138                         newdest = &opt->ip6po_dest2;
 3139                         break;
 3140                 }
 3141 
 3142                 /* turn off the previous option, then set the new option. */
 3143                 ip6_clearpktopts(opt, optname);
 3144                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
 3145                 if (*newdest == NULL)
 3146                         return (ENOBUFS);
 3147                 bcopy(dest, *newdest, destlen);
 3148 
 3149                 break;
 3150         }
 3151 
 3152         case IPV6_2292RTHDR:
 3153         case IPV6_RTHDR:
 3154         {
 3155                 struct ip6_rthdr *rth;
 3156                 int rthlen;
 3157 
 3158                 if (len == 0) {
 3159                         ip6_clearpktopts(opt, IPV6_RTHDR);
 3160                         break;  /* just remove the option */
 3161                 }
 3162 
 3163                 /* message length validation */
 3164                 if (len < sizeof(struct ip6_rthdr))
 3165                         return (EINVAL);
 3166                 rth = (struct ip6_rthdr *)buf;
 3167                 rthlen = (rth->ip6r_len + 1) << 3;
 3168                 if (len != rthlen)
 3169                         return (EINVAL);
 3170 
 3171                 switch (rth->ip6r_type) {
 3172                 case IPV6_RTHDR_TYPE_0:
 3173                         if (rth->ip6r_len == 0) /* must contain one addr */
 3174                                 return (EINVAL);
 3175                         if (rth->ip6r_len % 2) /* length must be even */
 3176                                 return (EINVAL);
 3177                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
 3178                                 return (EINVAL);
 3179                         break;
 3180                 default:
 3181                         return (EINVAL);        /* not supported */
 3182                 }
 3183 
 3184                 /* turn off the previous option */
 3185                 ip6_clearpktopts(opt, IPV6_RTHDR);
 3186                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
 3187                 if (opt->ip6po_rthdr == NULL)
 3188                         return (ENOBUFS);
 3189                 bcopy(rth, opt->ip6po_rthdr, rthlen);
 3190 
 3191                 break;
 3192         }
 3193 
 3194         case IPV6_USE_MIN_MTU:
 3195                 if (len != sizeof(int))
 3196                         return (EINVAL);
 3197                 minmtupolicy = *(int *)buf;
 3198                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
 3199                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
 3200                     minmtupolicy != IP6PO_MINMTU_ALL) {
 3201                         return (EINVAL);
 3202                 }
 3203                 opt->ip6po_minmtu = minmtupolicy;
 3204                 break;
 3205 
 3206         case IPV6_DONTFRAG:
 3207                 if (len != sizeof(int))
 3208                         return (EINVAL);
 3209 
 3210                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
 3211                         /*
 3212                          * we ignore this option for TCP sockets.
 3213                          * (RFC3542 leaves this case unspecified.)
 3214                          */
 3215                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
 3216                 } else
 3217                         opt->ip6po_flags |= IP6PO_DONTFRAG;
 3218                 break;
 3219 
 3220         case IPV6_PREFER_TEMPADDR:
 3221                 if (len != sizeof(int))
 3222                         return (EINVAL);
 3223                 preftemp = *(int *)buf;
 3224                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
 3225                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
 3226                     preftemp != IP6PO_TEMPADDR_PREFER) {
 3227                         return (EINVAL);
 3228                 }
 3229                 opt->ip6po_prefer_tempaddr = preftemp;
 3230                 break;
 3231 
 3232         default:
 3233                 return (ENOPROTOOPT);
 3234         } /* end of switch */
 3235 
 3236         return (0);
 3237 }
 3238 
 3239 /*
 3240  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
 3241  * packet to the input queue of a specified interface.  Note that this
 3242  * calls the output routine of the loopback "driver", but with an interface
 3243  * pointer that might NOT be &loif -- easier than replicating that code here.
 3244  */
 3245 void
 3246 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
 3247 {
 3248         struct mbuf *copym;
 3249         struct ip6_hdr *ip6;
 3250 
 3251         copym = m_copy(m, 0, M_COPYALL);
 3252         if (copym == NULL)
 3253                 return;
 3254 
 3255         /*
 3256          * Make sure to deep-copy IPv6 header portion in case the data
 3257          * is in an mbuf cluster, so that we can safely override the IPv6
 3258          * header portion later.
 3259          */
 3260         if ((copym->m_flags & M_EXT) != 0 ||
 3261             copym->m_len < sizeof(struct ip6_hdr)) {
 3262                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
 3263                 if (copym == NULL)
 3264                         return;
 3265         }
 3266 
 3267 #ifdef DIAGNOSTIC
 3268         if (copym->m_len < sizeof(*ip6)) {
 3269                 m_freem(copym);
 3270                 return;
 3271         }
 3272 #endif
 3273 
 3274         ip6 = mtod(copym, struct ip6_hdr *);
 3275         /*
 3276          * clear embedded scope identifiers if necessary.
 3277          * in6_clearscope will touch the addresses only when necessary.
 3278          */
 3279         in6_clearscope(&ip6->ip6_src);
 3280         in6_clearscope(&ip6->ip6_dst);
 3281 
 3282         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
 3283 }
 3284 
 3285 /*
 3286  * Chop IPv6 header off from the payload.
 3287  */
 3288 static int
 3289 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
 3290 {
 3291         struct mbuf *mh;
 3292         struct ip6_hdr *ip6;
 3293 
 3294         ip6 = mtod(m, struct ip6_hdr *);
 3295         if (m->m_len > sizeof(*ip6)) {
 3296                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
 3297                 if (mh == 0) {
 3298                         m_freem(m);
 3299                         return ENOBUFS;
 3300                 }
 3301                 M_MOVE_PKTHDR(mh, m);
 3302                 MH_ALIGN(mh, sizeof(*ip6));
 3303                 m->m_len -= sizeof(*ip6);
 3304                 m->m_data += sizeof(*ip6);
 3305                 mh->m_next = m;
 3306                 m = mh;
 3307                 m->m_len = sizeof(*ip6);
 3308                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
 3309         }
 3310         exthdrs->ip6e_ip6 = m;
 3311         return 0;
 3312 }
 3313 
 3314 /*
 3315  * Compute IPv6 extension header length.
 3316  */
 3317 int
 3318 ip6_optlen(struct inpcb *in6p)
 3319 {
 3320         int len;
 3321 
 3322         if (!in6p->in6p_outputopts)
 3323                 return 0;
 3324 
 3325         len = 0;
 3326 #define elen(x) \
 3327     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
 3328 
 3329         len += elen(in6p->in6p_outputopts->ip6po_hbh);
 3330         if (in6p->in6p_outputopts->ip6po_rthdr)
 3331                 /* dest1 is valid with rthdr only */
 3332                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
 3333         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
 3334         len += elen(in6p->in6p_outputopts->ip6po_dest2);
 3335         return len;
 3336 #undef elen
 3337 }

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