The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: 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("$FreeBSD$");
   65 
   66 #include "opt_inet.h"
   67 #include "opt_inet6.h"
   68 #include "opt_ipsec.h"
   69 #include "opt_sctp.h"
   70 
   71 #include <sys/param.h>
   72 #include <sys/kernel.h>
   73 #include <sys/malloc.h>
   74 #include <sys/mbuf.h>
   75 #include <sys/errno.h>
   76 #include <sys/priv.h>
   77 #include <sys/proc.h>
   78 #include <sys/protosw.h>
   79 #include <sys/socket.h>
   80 #include <sys/socketvar.h>
   81 #include <sys/syslog.h>
   82 #include <sys/ucred.h>
   83 
   84 #include <net/if.h>
   85 #include <net/netisr.h>
   86 #include <net/route.h>
   87 #include <net/pfil.h>
   88 #include <net/vnet.h>
   89 
   90 #include <netinet/in.h>
   91 #include <netinet/in_var.h>
   92 #include <netinet6/in6_var.h>
   93 #include <netinet/ip6.h>
   94 #include <netinet/icmp6.h>
   95 #include <netinet6/ip6_var.h>
   96 #include <netinet/in_pcb.h>
   97 #include <netinet/tcp_var.h>
   98 #include <netinet6/nd6.h>
   99 
  100 #ifdef IPSEC
  101 #include <netipsec/ipsec.h>
  102 #include <netipsec/ipsec6.h>
  103 #include <netipsec/key.h>
  104 #include <netinet6/ip6_ipsec.h>
  105 #endif /* IPSEC */
  106 #ifdef SCTP
  107 #include <netinet/sctp.h>
  108 #include <netinet/sctp_crc32.h>
  109 #endif
  110 
  111 #include <netinet6/ip6protosw.h>
  112 #include <netinet6/scope6_var.h>
  113 
  114 extern int in6_mcast_loop;
  115 
  116 struct ip6_exthdrs {
  117         struct mbuf *ip6e_ip6;
  118         struct mbuf *ip6e_hbh;
  119         struct mbuf *ip6e_dest1;
  120         struct mbuf *ip6e_rthdr;
  121         struct mbuf *ip6e_dest2;
  122 };
  123 
  124 static int ip6_pcbopt __P((int, u_char *, int, struct ip6_pktopts **,
  125                            struct ucred *, int));
  126 static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
  127         struct socket *, struct sockopt *));
  128 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
  129 static int ip6_setpktopt __P((int, u_char *, int, struct ip6_pktopts *,
  130         struct ucred *, int, int, int));
  131 
  132 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
  133 static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
  134         struct ip6_frag **));
  135 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
  136 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
  137 static int ip6_getpmtu __P((struct route_in6 *, struct route_in6 *,
  138         struct ifnet *, struct in6_addr *, u_long *, int *, u_int));
  139 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
  140 
  141 
  142 /*
  143  * Make an extension header from option data.  hp is the source, and
  144  * mp is the destination.
  145  */
  146 #define MAKE_EXTHDR(hp, mp)                                             \
  147     do {                                                                \
  148         if (hp) {                                                       \
  149                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
  150                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
  151                     ((eh)->ip6e_len + 1) << 3);                         \
  152                 if (error)                                              \
  153                         goto freehdrs;                                  \
  154         }                                                               \
  155     } while (/*CONSTCOND*/ 0)
  156 
  157 /*
  158  * Form a chain of extension headers.
  159  * m is the extension header mbuf
  160  * mp is the previous mbuf in the chain
  161  * p is the next header
  162  * i is the type of option.
  163  */
  164 #define MAKE_CHAIN(m, mp, p, i)\
  165     do {\
  166         if (m) {\
  167                 if (!hdrsplit) \
  168                         panic("assumption failed: hdr not split"); \
  169                 *mtod((m), u_char *) = *(p);\
  170                 *(p) = (i);\
  171                 p = mtod((m), u_char *);\
  172                 (m)->m_next = (mp)->m_next;\
  173                 (mp)->m_next = (m);\
  174                 (mp) = (m);\
  175         }\
  176     } while (/*CONSTCOND*/ 0)
  177 
  178 /*
  179  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
  180  * header (with pri, len, nxt, hlim, src, dst).
  181  * This function may modify ver and hlim only.
  182  * The mbuf chain containing the packet will be freed.
  183  * The mbuf opt, if present, will not be freed.
  184  *
  185  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
  186  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
  187  * which is rt_rmx.rmx_mtu.
  188  *
  189  * ifpp - XXX: just for statistics
  190  */
  191 int
  192 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
  193     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
  194     struct ifnet **ifpp, struct inpcb *inp)
  195 {
  196         struct ip6_hdr *ip6, *mhip6;
  197         struct ifnet *ifp, *origifp;
  198         struct mbuf *m = m0;
  199         struct mbuf *mprev = NULL;
  200         int hlen, tlen, len, off;
  201         struct route_in6 ip6route;
  202         struct rtentry *rt = NULL;
  203         struct sockaddr_in6 *dst, src_sa, dst_sa;
  204         struct in6_addr odst;
  205         int error = 0;
  206         struct in6_ifaddr *ia = NULL;
  207         u_long mtu;
  208         int alwaysfrag, dontfrag;
  209         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
  210         struct ip6_exthdrs exthdrs;
  211         struct in6_addr finaldst, src0, dst0;
  212         u_int32_t zone;
  213         struct route_in6 *ro_pmtu = NULL;
  214         int hdrsplit = 0;
  215         int needipsec = 0;
  216 #ifdef SCTP
  217         int sw_csum;
  218 #endif
  219 #ifdef IPSEC
  220         struct ipsec_output_state state;
  221         struct ip6_rthdr *rh = NULL;
  222         int needipsectun = 0;
  223         int segleft_org = 0;
  224         struct secpolicy *sp = NULL;
  225 #endif /* IPSEC */
  226 
  227         ip6 = mtod(m, struct ip6_hdr *);
  228         if (ip6 == NULL) {
  229                 printf ("ip6 is NULL");
  230                 goto bad;
  231         }
  232 
  233         if (inp != NULL)
  234                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
  235 
  236         finaldst = ip6->ip6_dst;
  237 
  238         bzero(&exthdrs, sizeof(exthdrs));
  239 
  240         if (opt) {
  241                 /* Hop-by-Hop options header */
  242                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
  243                 /* Destination options header(1st part) */
  244                 if (opt->ip6po_rthdr) {
  245                         /*
  246                          * Destination options header(1st part)
  247                          * This only makes sense with a routing header.
  248                          * See Section 9.2 of RFC 3542.
  249                          * Disabling this part just for MIP6 convenience is
  250                          * a bad idea.  We need to think carefully about a
  251                          * way to make the advanced API coexist with MIP6
  252                          * options, which might automatically be inserted in
  253                          * the kernel.
  254                          */
  255                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
  256                 }
  257                 /* Routing header */
  258                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
  259                 /* Destination options header(2nd part) */
  260                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
  261         }
  262 
  263 #ifdef IPSEC
  264         /*
  265          * IPSec checking which handles several cases.
  266          * FAST IPSEC: We re-injected the packet.
  267          */
  268         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
  269         {
  270         case 1:                 /* Bad packet */
  271                 goto freehdrs;
  272         case -1:                /* Do IPSec */
  273                 needipsec = 1;
  274         case 0:                 /* No IPSec */
  275         default:
  276                 break;
  277         }
  278 #endif /* IPSEC */
  279 
  280         /*
  281          * Calculate the total length of the extension header chain.
  282          * Keep the length of the unfragmentable part for fragmentation.
  283          */
  284         optlen = 0;
  285         if (exthdrs.ip6e_hbh)
  286                 optlen += exthdrs.ip6e_hbh->m_len;
  287         if (exthdrs.ip6e_dest1)
  288                 optlen += exthdrs.ip6e_dest1->m_len;
  289         if (exthdrs.ip6e_rthdr)
  290                 optlen += exthdrs.ip6e_rthdr->m_len;
  291         unfragpartlen = optlen + sizeof(struct ip6_hdr);
  292 
  293         /* NOTE: we don't add AH/ESP length here. do that later. */
  294         if (exthdrs.ip6e_dest2)
  295                 optlen += exthdrs.ip6e_dest2->m_len;
  296 
  297         /*
  298          * If we need IPsec, or there is at least one extension header,
  299          * separate IP6 header from the payload.
  300          */
  301         if ((needipsec || optlen) && !hdrsplit) {
  302                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
  303                         m = NULL;
  304                         goto freehdrs;
  305                 }
  306                 m = exthdrs.ip6e_ip6;
  307                 hdrsplit++;
  308         }
  309 
  310         /* adjust pointer */
  311         ip6 = mtod(m, struct ip6_hdr *);
  312 
  313         /* adjust mbuf packet header length */
  314         m->m_pkthdr.len += optlen;
  315         plen = m->m_pkthdr.len - sizeof(*ip6);
  316 
  317         /* If this is a jumbo payload, insert a jumbo payload option. */
  318         if (plen > IPV6_MAXPACKET) {
  319                 if (!hdrsplit) {
  320                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
  321                                 m = NULL;
  322                                 goto freehdrs;
  323                         }
  324                         m = exthdrs.ip6e_ip6;
  325                         hdrsplit++;
  326                 }
  327                 /* adjust pointer */
  328                 ip6 = mtod(m, struct ip6_hdr *);
  329                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
  330                         goto freehdrs;
  331                 ip6->ip6_plen = 0;
  332         } else
  333                 ip6->ip6_plen = htons(plen);
  334 
  335         /*
  336          * Concatenate headers and fill in next header fields.
  337          * Here we have, on "m"
  338          *      IPv6 payload
  339          * and we insert headers accordingly.  Finally, we should be getting:
  340          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
  341          *
  342          * during the header composing process, "m" points to IPv6 header.
  343          * "mprev" points to an extension header prior to esp.
  344          */
  345         u_char *nexthdrp = &ip6->ip6_nxt;
  346         mprev = m;
  347 
  348         /*
  349          * we treat dest2 specially.  this makes IPsec processing
  350          * much easier.  the goal here is to make mprev point the
  351          * mbuf prior to dest2.
  352          *
  353          * result: IPv6 dest2 payload
  354          * m and mprev will point to IPv6 header.
  355          */
  356         if (exthdrs.ip6e_dest2) {
  357                 if (!hdrsplit)
  358                         panic("assumption failed: hdr not split");
  359                 exthdrs.ip6e_dest2->m_next = m->m_next;
  360                 m->m_next = exthdrs.ip6e_dest2;
  361                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
  362                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
  363         }
  364 
  365         /*
  366          * result: IPv6 hbh dest1 rthdr dest2 payload
  367          * m will point to IPv6 header.  mprev will point to the
  368          * extension header prior to dest2 (rthdr in the above case).
  369          */
  370         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
  371         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
  372                    IPPROTO_DSTOPTS);
  373         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
  374                    IPPROTO_ROUTING);
  375 
  376 #ifdef IPSEC
  377         if (!needipsec)
  378                 goto skip_ipsec2;
  379 
  380         /*
  381          * pointers after IPsec headers are not valid any more.
  382          * other pointers need a great care too.
  383          * (IPsec routines should not mangle mbufs prior to AH/ESP)
  384          */
  385         exthdrs.ip6e_dest2 = NULL;
  386 
  387         if (exthdrs.ip6e_rthdr) {
  388                 rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
  389                 segleft_org = rh->ip6r_segleft;
  390                 rh->ip6r_segleft = 0;
  391         }
  392 
  393         bzero(&state, sizeof(state));
  394         state.m = m;
  395         error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
  396                                     &needipsectun);
  397         m = state.m;
  398         if (error == EJUSTRETURN) {
  399                 /*
  400                  * We had a SP with a level of 'use' and no SA. We
  401                  * will just continue to process the packet without
  402                  * IPsec processing.
  403                  */
  404                 ;
  405         } else if (error) {
  406                 /* mbuf is already reclaimed in ipsec6_output_trans. */
  407                 m = NULL;
  408                 switch (error) {
  409                 case EHOSTUNREACH:
  410                 case ENETUNREACH:
  411                 case EMSGSIZE:
  412                 case ENOBUFS:
  413                 case ENOMEM:
  414                         break;
  415                 default:
  416                         printf("[%s:%d] (ipsec): error code %d\n",
  417                             __func__, __LINE__, error);
  418                         /* FALLTHROUGH */
  419                 case ENOENT:
  420                         /* don't show these error codes to the user */
  421                         error = 0;
  422                         break;
  423                 }
  424                 goto bad;
  425         } else if (!needipsectun) {
  426                 /*
  427                  * In the FAST IPSec case we have already
  428                  * re-injected the packet and it has been freed
  429                  * by the ipsec_done() function.  So, just clean
  430                  * up after ourselves.
  431                  */
  432                 m = NULL;
  433                 goto done;
  434         }
  435         if (exthdrs.ip6e_rthdr) {
  436                 /* ah6_output doesn't modify mbuf chain */
  437                 rh->ip6r_segleft = segleft_org;
  438         }
  439 skip_ipsec2:;
  440 #endif /* IPSEC */
  441 
  442         /*
  443          * If there is a routing header, discard the packet.
  444          */
  445         if (exthdrs.ip6e_rthdr) {
  446                  error = EINVAL;
  447                  goto bad;
  448         }
  449 
  450         /* Source address validation */
  451         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
  452             (flags & IPV6_UNSPECSRC) == 0) {
  453                 error = EOPNOTSUPP;
  454                 V_ip6stat.ip6s_badscope++;
  455                 goto bad;
  456         }
  457         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
  458                 error = EOPNOTSUPP;
  459                 V_ip6stat.ip6s_badscope++;
  460                 goto bad;
  461         }
  462 
  463         V_ip6stat.ip6s_localout++;
  464 
  465         /*
  466          * Route packet.
  467          */
  468         if (ro == 0) {
  469                 ro = &ip6route;
  470                 bzero((caddr_t)ro, sizeof(*ro));
  471         }
  472         ro_pmtu = ro;
  473         if (opt && opt->ip6po_rthdr)
  474                 ro = &opt->ip6po_route;
  475         dst = (struct sockaddr_in6 *)&ro->ro_dst;
  476 
  477 again:
  478         /*
  479          * if specified, try to fill in the traffic class field.
  480          * do not override if a non-zero value is already set.
  481          * we check the diffserv field and the ecn field separately.
  482          */
  483         if (opt && opt->ip6po_tclass >= 0) {
  484                 int mask = 0;
  485 
  486                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
  487                         mask |= 0xfc;
  488                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
  489                         mask |= 0x03;
  490                 if (mask != 0)
  491                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
  492         }
  493 
  494         /* fill in or override the hop limit field, if necessary. */
  495         if (opt && opt->ip6po_hlim != -1)
  496                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
  497         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
  498                 if (im6o != NULL)
  499                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
  500                 else
  501                         ip6->ip6_hlim = V_ip6_defmcasthlim;
  502         }
  503 
  504 #ifdef IPSEC
  505         /*
  506          * We may re-inject packets into the stack here.
  507          */
  508         if (needipsec && needipsectun) {
  509                 struct ipsec_output_state state;
  510 
  511                 /*
  512                  * All the extension headers will become inaccessible
  513                  * (since they can be encrypted).
  514                  * Don't panic, we need no more updates to extension headers
  515                  * on inner IPv6 packet (since they are now encapsulated).
  516                  *
  517                  * IPv6 [ESP|AH] IPv6 [extension headers] payload
  518                  */
  519                 bzero(&exthdrs, sizeof(exthdrs));
  520                 exthdrs.ip6e_ip6 = m;
  521 
  522                 bzero(&state, sizeof(state));
  523                 state.m = m;
  524                 state.ro = (struct route *)ro;
  525                 state.dst = (struct sockaddr *)dst;
  526 
  527                 error = ipsec6_output_tunnel(&state, sp, flags);
  528 
  529                 m = state.m;
  530                 ro = (struct route_in6 *)state.ro;
  531                 dst = (struct sockaddr_in6 *)state.dst;
  532                 if (error == EJUSTRETURN) {
  533                         /*
  534                          * We had a SP with a level of 'use' and no SA. We
  535                          * will just continue to process the packet without
  536                          * IPsec processing.
  537                          */
  538                         ;
  539                 } else if (error) {
  540                         /* mbuf is already reclaimed in ipsec6_output_tunnel. */
  541                         m0 = m = NULL;
  542                         m = NULL;
  543                         switch (error) {
  544                         case EHOSTUNREACH:
  545                         case ENETUNREACH:
  546                         case EMSGSIZE:
  547                         case ENOBUFS:
  548                         case ENOMEM:
  549                                 break;
  550                         default:
  551                                 printf("[%s:%d] (ipsec): error code %d\n",
  552                                     __func__, __LINE__, error);
  553                                 /* FALLTHROUGH */
  554                         case ENOENT:
  555                                 /* don't show these error codes to the user */
  556                                 error = 0;
  557                                 break;
  558                         }
  559                         goto bad;
  560                 } else {
  561                         /*
  562                          * In the FAST IPSec case we have already
  563                          * re-injected the packet and it has been freed
  564                          * by the ipsec_done() function.  So, just clean
  565                          * up after ourselves.
  566                          */
  567                         m = NULL;
  568                         goto done;
  569                 }
  570 
  571                 exthdrs.ip6e_ip6 = m;
  572         }
  573 #endif /* IPSEC */
  574 
  575         /* adjust pointer */
  576         ip6 = mtod(m, struct ip6_hdr *);
  577 
  578         bzero(&dst_sa, sizeof(dst_sa));
  579         dst_sa.sin6_family = AF_INET6;
  580         dst_sa.sin6_len = sizeof(dst_sa);
  581         dst_sa.sin6_addr = ip6->ip6_dst;
  582         if ((error = in6_selectroute_fib(&dst_sa, opt, im6o, ro,
  583             &ifp, &rt, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m))) != 0) {
  584                 switch (error) {
  585                 case EHOSTUNREACH:
  586                         V_ip6stat.ip6s_noroute++;
  587                         break;
  588                 case EADDRNOTAVAIL:
  589                 default:
  590                         break; /* XXX statistics? */
  591                 }
  592                 if (ifp != NULL)
  593                         in6_ifstat_inc(ifp, ifs6_out_discard);
  594                 goto bad;
  595         }
  596         if (rt == NULL) {
  597                 /*
  598                  * If in6_selectroute() does not return a route entry,
  599                  * dst may not have been updated.
  600                  */
  601                 *dst = dst_sa;  /* XXX */
  602         }
  603 
  604         /*
  605          * then rt (for unicast) and ifp must be non-NULL valid values.
  606          */
  607         if ((flags & IPV6_FORWARDING) == 0) {
  608                 /* XXX: the FORWARDING flag can be set for mrouting. */
  609                 in6_ifstat_inc(ifp, ifs6_out_request);
  610         }
  611         if (rt != NULL) {
  612                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
  613                 rt->rt_use++;
  614         }
  615 
  616 
  617         /*
  618          * The outgoing interface must be in the zone of source and
  619          * destination addresses.  
  620          */
  621         origifp = ifp;
  622 
  623         src0 = ip6->ip6_src;
  624         if (in6_setscope(&src0, origifp, &zone))
  625                 goto badscope;
  626         bzero(&src_sa, sizeof(src_sa));
  627         src_sa.sin6_family = AF_INET6;
  628         src_sa.sin6_len = sizeof(src_sa);
  629         src_sa.sin6_addr = ip6->ip6_src;
  630         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
  631                 goto badscope;
  632 
  633         dst0 = ip6->ip6_dst;
  634         if (in6_setscope(&dst0, origifp, &zone))
  635                 goto badscope;
  636         /* re-initialize to be sure */
  637         bzero(&dst_sa, sizeof(dst_sa));
  638         dst_sa.sin6_family = AF_INET6;
  639         dst_sa.sin6_len = sizeof(dst_sa);
  640         dst_sa.sin6_addr = ip6->ip6_dst;
  641         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
  642                 goto badscope;
  643         }
  644 
  645         /* We should use ia_ifp to support the case of 
  646          * sending packets to an address of our own.
  647          */
  648         if (ia != NULL && ia->ia_ifp)
  649                 ifp = ia->ia_ifp;
  650 
  651         /* scope check is done. */
  652         goto routefound;
  653 
  654   badscope:
  655         V_ip6stat.ip6s_badscope++;
  656         in6_ifstat_inc(origifp, ifs6_out_discard);
  657         if (error == 0)
  658                 error = EHOSTUNREACH; /* XXX */
  659         goto bad;
  660 
  661   routefound:
  662         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
  663                 if (opt && opt->ip6po_nextroute.ro_rt) {
  664                         /*
  665                          * The nexthop is explicitly specified by the
  666                          * application.  We assume the next hop is an IPv6
  667                          * address.
  668                          */
  669                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
  670                 }
  671                 else if ((rt->rt_flags & RTF_GATEWAY))
  672                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
  673         }
  674 
  675         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
  676                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
  677         } else {
  678                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
  679                 in6_ifstat_inc(ifp, ifs6_out_mcast);
  680                 /*
  681                  * Confirm that the outgoing interface supports multicast.
  682                  */
  683                 if (!(ifp->if_flags & IFF_MULTICAST)) {
  684                         V_ip6stat.ip6s_noroute++;
  685                         in6_ifstat_inc(ifp, ifs6_out_discard);
  686                         error = ENETUNREACH;
  687                         goto bad;
  688                 }
  689                 if ((im6o == NULL && in6_mcast_loop) ||
  690                     (im6o && im6o->im6o_multicast_loop)) {
  691                         /*
  692                          * Loop back multicast datagram if not expressly
  693                          * forbidden to do so, even if we have not joined
  694                          * the address; protocols will filter it later,
  695                          * thus deferring a hash lookup and lock acquisition
  696                          * at the expense of an m_copym().
  697                          */
  698                         ip6_mloopback(ifp, m, dst);
  699                 } else {
  700                         /*
  701                          * If we are acting as a multicast router, perform
  702                          * multicast forwarding as if the packet had just
  703                          * arrived on the interface to which we are about
  704                          * to send.  The multicast forwarding function
  705                          * recursively calls this function, using the
  706                          * IPV6_FORWARDING flag to prevent infinite recursion.
  707                          *
  708                          * Multicasts that are looped back by ip6_mloopback(),
  709                          * above, will be forwarded by the ip6_input() routine,
  710                          * if necessary.
  711                          */
  712                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
  713                                 /*
  714                                  * XXX: ip6_mforward expects that rcvif is NULL
  715                                  * when it is called from the originating path.
  716                                  * However, it is not always the case, since
  717                                  * some versions of MGETHDR() does not
  718                                  * initialize the field.
  719                                  */
  720                                 m->m_pkthdr.rcvif = NULL;
  721                                 if (ip6_mforward(ip6, ifp, m) != 0) {
  722                                         m_freem(m);
  723                                         goto done;
  724                                 }
  725                         }
  726                 }
  727                 /*
  728                  * Multicasts with a hoplimit of zero may be looped back,
  729                  * above, but must not be transmitted on a network.
  730                  * Also, multicasts addressed to the loopback interface
  731                  * are not sent -- the above call to ip6_mloopback() will
  732                  * loop back a copy if this host actually belongs to the
  733                  * destination group on the loopback interface.
  734                  */
  735                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
  736                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
  737                         m_freem(m);
  738                         goto done;
  739                 }
  740         }
  741 
  742         /*
  743          * Fill the outgoing inteface to tell the upper layer
  744          * to increment per-interface statistics.
  745          */
  746         if (ifpp)
  747                 *ifpp = ifp;
  748 
  749         /* Determine path MTU. */
  750         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
  751             &alwaysfrag, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m))) != 0)
  752                 goto bad;
  753 
  754         /*
  755          * The caller of this function may specify to use the minimum MTU
  756          * in some cases.
  757          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
  758          * setting.  The logic is a bit complicated; by default, unicast
  759          * packets will follow path MTU while multicast packets will be sent at
  760          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
  761          * including unicast ones will be sent at the minimum MTU.  Multicast
  762          * packets will always be sent at the minimum MTU unless
  763          * IP6PO_MINMTU_DISABLE is explicitly specified.
  764          * See RFC 3542 for more details.
  765          */
  766         if (mtu > IPV6_MMTU) {
  767                 if ((flags & IPV6_MINMTU))
  768                         mtu = IPV6_MMTU;
  769                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
  770                         mtu = IPV6_MMTU;
  771                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
  772                          (opt == NULL ||
  773                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
  774                         mtu = IPV6_MMTU;
  775                 }
  776         }
  777 
  778         /*
  779          * clear embedded scope identifiers if necessary.
  780          * in6_clearscope will touch the addresses only when necessary.
  781          */
  782         in6_clearscope(&ip6->ip6_src);
  783         in6_clearscope(&ip6->ip6_dst);
  784 
  785         /*
  786          * If the outgoing packet contains a hop-by-hop options header,
  787          * it must be examined and processed even by the source node.
  788          * (RFC 2460, section 4.)
  789          */
  790         if (exthdrs.ip6e_hbh) {
  791                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
  792                 u_int32_t dummy; /* XXX unused */
  793                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
  794 
  795 #ifdef DIAGNOSTIC
  796                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
  797                         panic("ip6e_hbh is not continuous");
  798 #endif
  799                 /*
  800                  *  XXX: if we have to send an ICMPv6 error to the sender,
  801                  *       we need the M_LOOP flag since icmp6_error() expects
  802                  *       the IPv6 and the hop-by-hop options header are
  803                  *       continuous unless the flag is set.
  804                  */
  805                 m->m_flags |= M_LOOP;
  806                 m->m_pkthdr.rcvif = ifp;
  807                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
  808                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
  809                     &dummy, &plen) < 0) {
  810                         /* m was already freed at this point */
  811                         error = EINVAL;/* better error? */
  812                         goto done;
  813                 }
  814                 m->m_flags &= ~M_LOOP; /* XXX */
  815                 m->m_pkthdr.rcvif = NULL;
  816         }
  817 
  818         /* Jump over all PFIL processing if hooks are not active. */
  819         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
  820                 goto passout;
  821 
  822         odst = ip6->ip6_dst;
  823         /* Run through list of hooks for output packets. */
  824         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
  825         if (error != 0 || m == NULL)
  826                 goto done;
  827         ip6 = mtod(m, struct ip6_hdr *);
  828 
  829         /* See if destination IP address was changed by packet filter. */
  830         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
  831                 m->m_flags |= M_SKIP_FIREWALL;
  832                 /* If destination is now ourself drop to ip6_input(). */
  833                 if (in6_localaddr(&ip6->ip6_dst)) {
  834                         if (m->m_pkthdr.rcvif == NULL)
  835                                 m->m_pkthdr.rcvif = V_loif;
  836                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
  837                                 m->m_pkthdr.csum_flags |=
  838                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
  839                                 m->m_pkthdr.csum_data = 0xffff;
  840                         }
  841                         m->m_pkthdr.csum_flags |=
  842                             CSUM_IP_CHECKED | CSUM_IP_VALID;
  843 #ifdef SCTP
  844                         if (m->m_pkthdr.csum_flags & CSUM_SCTP)
  845                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
  846 #endif
  847                         error = netisr_queue(NETISR_IPV6, m);
  848                         goto done;
  849                 } else
  850                         goto again;     /* Redo the routing table lookup. */
  851         }
  852 
  853         /* XXX: IPFIREWALL_FORWARD */
  854 
  855 passout:
  856         /*
  857          * Send the packet to the outgoing interface.
  858          * If necessary, do IPv6 fragmentation before sending.
  859          *
  860          * the logic here is rather complex:
  861          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
  862          * 1-a: send as is if tlen <= path mtu
  863          * 1-b: fragment if tlen > path mtu
  864          *
  865          * 2: if user asks us not to fragment (dontfrag == 1)
  866          * 2-a: send as is if tlen <= interface mtu
  867          * 2-b: error if tlen > interface mtu
  868          *
  869          * 3: if we always need to attach fragment header (alwaysfrag == 1)
  870          *      always fragment
  871          *
  872          * 4: if dontfrag == 1 && alwaysfrag == 1
  873          *      error, as we cannot handle this conflicting request
  874          */
  875 #ifdef SCTP
  876         sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
  877         if (sw_csum & CSUM_SCTP) {
  878                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
  879                 sw_csum &= ~CSUM_SCTP;
  880         }
  881 #endif
  882         tlen = m->m_pkthdr.len;
  883 
  884         if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
  885                 dontfrag = 1;
  886         else
  887                 dontfrag = 0;
  888         if (dontfrag && alwaysfrag) {   /* case 4 */
  889                 /* conflicting request - can't transmit */
  890                 error = EMSGSIZE;
  891                 goto bad;
  892         }
  893         if (dontfrag && tlen > IN6_LINKMTU(ifp)) {      /* case 2-b */
  894                 /*
  895                  * Even if the DONTFRAG option is specified, we cannot send the
  896                  * packet when the data length is larger than the MTU of the
  897                  * outgoing interface.
  898                  * Notify the error by sending IPV6_PATHMTU ancillary data as
  899                  * well as returning an error code (the latter is not described
  900                  * in the API spec.)
  901                  */
  902                 u_int32_t mtu32;
  903                 struct ip6ctlparam ip6cp;
  904 
  905                 mtu32 = (u_int32_t)mtu;
  906                 bzero(&ip6cp, sizeof(ip6cp));
  907                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
  908                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
  909                     (void *)&ip6cp);
  910 
  911                 error = EMSGSIZE;
  912                 goto bad;
  913         }
  914 
  915         /*
  916          * transmit packet without fragmentation
  917          */
  918         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
  919                 struct in6_ifaddr *ia6;
  920 
  921                 ip6 = mtod(m, struct ip6_hdr *);
  922                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
  923                 if (ia6) {
  924                         /* Record statistics for this interface address. */
  925                         ia6->ia_ifa.if_opackets++;
  926                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
  927                         ifa_free(&ia6->ia_ifa);
  928                 }
  929                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
  930                 goto done;
  931         }
  932 
  933         /*
  934          * try to fragment the packet.  case 1-b and 3
  935          */
  936         if (mtu < IPV6_MMTU) {
  937                 /* path MTU cannot be less than IPV6_MMTU */
  938                 error = EMSGSIZE;
  939                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
  940                 goto bad;
  941         } else if (ip6->ip6_plen == 0) {
  942                 /* jumbo payload cannot be fragmented */
  943                 error = EMSGSIZE;
  944                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
  945                 goto bad;
  946         } else {
  947                 struct mbuf **mnext, *m_frgpart;
  948                 struct ip6_frag *ip6f;
  949                 u_int32_t id = htonl(ip6_randomid());
  950                 u_char nextproto;
  951 
  952                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
  953 
  954                 /*
  955                  * Too large for the destination or interface;
  956                  * fragment if possible.
  957                  * Must be able to put at least 8 bytes per fragment.
  958                  */
  959                 hlen = unfragpartlen;
  960                 if (mtu > IPV6_MAXPACKET)
  961                         mtu = IPV6_MAXPACKET;
  962 
  963                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
  964                 if (len < 8) {
  965                         error = EMSGSIZE;
  966                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
  967                         goto bad;
  968                 }
  969 
  970                 /*
  971                  * Verify that we have any chance at all of being able to queue
  972                  *      the packet or packet fragments
  973                  */
  974                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
  975                     < tlen  /* - hlen */)) {
  976                         error = ENOBUFS;
  977                         V_ip6stat.ip6s_odropped++;
  978                         goto bad;
  979                 }
  980 
  981                 mnext = &m->m_nextpkt;
  982 
  983                 /*
  984                  * Change the next header field of the last header in the
  985                  * unfragmentable part.
  986                  */
  987                 if (exthdrs.ip6e_rthdr) {
  988                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
  989                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
  990                 } else if (exthdrs.ip6e_dest1) {
  991                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
  992                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
  993                 } else if (exthdrs.ip6e_hbh) {
  994                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
  995                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
  996                 } else {
  997                         nextproto = ip6->ip6_nxt;
  998                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
  999                 }
 1000 
 1001                 /*
 1002                  * Loop through length of segment after first fragment,
 1003                  * make new header and copy data of each part and link onto
 1004                  * chain.
 1005                  */
 1006                 m0 = m;
 1007                 for (off = hlen; off < tlen; off += len) {
 1008                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
 1009                         if (!m) {
 1010                                 error = ENOBUFS;
 1011                                 V_ip6stat.ip6s_odropped++;
 1012                                 goto sendorfree;
 1013                         }
 1014                         m->m_pkthdr.rcvif = NULL;
 1015                         m->m_flags = m0->m_flags & M_COPYFLAGS; /* incl. FIB */
 1016                         *mnext = m;
 1017                         mnext = &m->m_nextpkt;
 1018                         m->m_data += max_linkhdr;
 1019                         mhip6 = mtod(m, struct ip6_hdr *);
 1020                         *mhip6 = *ip6;
 1021                         m->m_len = sizeof(*mhip6);
 1022                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
 1023                         if (error) {
 1024                                 V_ip6stat.ip6s_odropped++;
 1025                                 goto sendorfree;
 1026                         }
 1027                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
 1028                         if (off + len >= tlen)
 1029                                 len = tlen - off;
 1030                         else
 1031                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
 1032                         mhip6->ip6_plen = htons((u_short)(len + hlen +
 1033                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
 1034                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
 1035                                 error = ENOBUFS;
 1036                                 V_ip6stat.ip6s_odropped++;
 1037                                 goto sendorfree;
 1038                         }
 1039                         m_cat(m, m_frgpart);
 1040                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
 1041                         m->m_pkthdr.rcvif = NULL;
 1042                         ip6f->ip6f_reserved = 0;
 1043                         ip6f->ip6f_ident = id;
 1044                         ip6f->ip6f_nxt = nextproto;
 1045                         V_ip6stat.ip6s_ofragments++;
 1046                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
 1047                 }
 1048 
 1049                 in6_ifstat_inc(ifp, ifs6_out_fragok);
 1050         }
 1051 
 1052         /*
 1053          * Remove leading garbages.
 1054          */
 1055 sendorfree:
 1056         m = m0->m_nextpkt;
 1057         m0->m_nextpkt = 0;
 1058         m_freem(m0);
 1059         for (m0 = m; m; m = m0) {
 1060                 m0 = m->m_nextpkt;
 1061                 m->m_nextpkt = 0;
 1062                 if (error == 0) {
 1063                         /* Record statistics for this interface address. */
 1064                         if (ia) {
 1065                                 ia->ia_ifa.if_opackets++;
 1066                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
 1067                         }
 1068                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
 1069                 } else
 1070                         m_freem(m);
 1071         }
 1072 
 1073         if (error == 0)
 1074                 V_ip6stat.ip6s_fragmented++;
 1075 
 1076 done:
 1077         if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
 1078                 RTFREE(ro->ro_rt);
 1079         } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
 1080                 RTFREE(ro_pmtu->ro_rt);
 1081         }
 1082 #ifdef IPSEC
 1083         if (sp != NULL)
 1084                 KEY_FREESP(&sp);
 1085 #endif
 1086 
 1087         return (error);
 1088 
 1089 freehdrs:
 1090         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
 1091         m_freem(exthdrs.ip6e_dest1);
 1092         m_freem(exthdrs.ip6e_rthdr);
 1093         m_freem(exthdrs.ip6e_dest2);
 1094         /* FALLTHROUGH */
 1095 bad:
 1096         if (m)
 1097                 m_freem(m);
 1098         goto done;
 1099 }
 1100 
 1101 static int
 1102 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
 1103 {
 1104         struct mbuf *m;
 1105 
 1106         if (hlen > MCLBYTES)
 1107                 return (ENOBUFS); /* XXX */
 1108 
 1109         MGET(m, M_DONTWAIT, MT_DATA);
 1110         if (!m)
 1111                 return (ENOBUFS);
 1112 
 1113         if (hlen > MLEN) {
 1114                 MCLGET(m, M_DONTWAIT);
 1115                 if ((m->m_flags & M_EXT) == 0) {
 1116                         m_free(m);
 1117                         return (ENOBUFS);
 1118                 }
 1119         }
 1120         m->m_len = hlen;
 1121         if (hdr)
 1122                 bcopy(hdr, mtod(m, caddr_t), hlen);
 1123 
 1124         *mp = m;
 1125         return (0);
 1126 }
 1127 
 1128 /*
 1129  * Insert jumbo payload option.
 1130  */
 1131 static int
 1132 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
 1133 {
 1134         struct mbuf *mopt;
 1135         u_char *optbuf;
 1136         u_int32_t v;
 1137 
 1138 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
 1139 
 1140         /*
 1141          * If there is no hop-by-hop options header, allocate new one.
 1142          * If there is one but it doesn't have enough space to store the
 1143          * jumbo payload option, allocate a cluster to store the whole options.
 1144          * Otherwise, use it to store the options.
 1145          */
 1146         if (exthdrs->ip6e_hbh == 0) {
 1147                 MGET(mopt, M_DONTWAIT, MT_DATA);
 1148                 if (mopt == 0)
 1149                         return (ENOBUFS);
 1150                 mopt->m_len = JUMBOOPTLEN;
 1151                 optbuf = mtod(mopt, u_char *);
 1152                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
 1153                 exthdrs->ip6e_hbh = mopt;
 1154         } else {
 1155                 struct ip6_hbh *hbh;
 1156 
 1157                 mopt = exthdrs->ip6e_hbh;
 1158                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
 1159                         /*
 1160                          * XXX assumption:
 1161                          * - exthdrs->ip6e_hbh is not referenced from places
 1162                          *   other than exthdrs.
 1163                          * - exthdrs->ip6e_hbh is not an mbuf chain.
 1164                          */
 1165                         int oldoptlen = mopt->m_len;
 1166                         struct mbuf *n;
 1167 
 1168                         /*
 1169                          * XXX: give up if the whole (new) hbh header does
 1170                          * not fit even in an mbuf cluster.
 1171                          */
 1172                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
 1173                                 return (ENOBUFS);
 1174 
 1175                         /*
 1176                          * As a consequence, we must always prepare a cluster
 1177                          * at this point.
 1178                          */
 1179                         MGET(n, M_DONTWAIT, MT_DATA);
 1180                         if (n) {
 1181                                 MCLGET(n, M_DONTWAIT);
 1182                                 if ((n->m_flags & M_EXT) == 0) {
 1183                                         m_freem(n);
 1184                                         n = NULL;
 1185                                 }
 1186                         }
 1187                         if (!n)
 1188                                 return (ENOBUFS);
 1189                         n->m_len = oldoptlen + JUMBOOPTLEN;
 1190                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
 1191                             oldoptlen);
 1192                         optbuf = mtod(n, caddr_t) + oldoptlen;
 1193                         m_freem(mopt);
 1194                         mopt = exthdrs->ip6e_hbh = n;
 1195                 } else {
 1196                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
 1197                         mopt->m_len += JUMBOOPTLEN;
 1198                 }
 1199                 optbuf[0] = IP6OPT_PADN;
 1200                 optbuf[1] = 1;
 1201 
 1202                 /*
 1203                  * Adjust the header length according to the pad and
 1204                  * the jumbo payload option.
 1205                  */
 1206                 hbh = mtod(mopt, struct ip6_hbh *);
 1207                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
 1208         }
 1209 
 1210         /* fill in the option. */
 1211         optbuf[2] = IP6OPT_JUMBO;
 1212         optbuf[3] = 4;
 1213         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
 1214         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
 1215 
 1216         /* finally, adjust the packet header length */
 1217         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
 1218 
 1219         return (0);
 1220 #undef JUMBOOPTLEN
 1221 }
 1222 
 1223 /*
 1224  * Insert fragment header and copy unfragmentable header portions.
 1225  */
 1226 static int
 1227 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
 1228     struct ip6_frag **frghdrp)
 1229 {
 1230         struct mbuf *n, *mlast;
 1231 
 1232         if (hlen > sizeof(struct ip6_hdr)) {
 1233                 n = m_copym(m0, sizeof(struct ip6_hdr),
 1234                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
 1235                 if (n == 0)
 1236                         return (ENOBUFS);
 1237                 m->m_next = n;
 1238         } else
 1239                 n = m;
 1240 
 1241         /* Search for the last mbuf of unfragmentable part. */
 1242         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
 1243                 ;
 1244 
 1245         if ((mlast->m_flags & M_EXT) == 0 &&
 1246             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
 1247                 /* use the trailing space of the last mbuf for the fragment hdr */
 1248                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
 1249                     mlast->m_len);
 1250                 mlast->m_len += sizeof(struct ip6_frag);
 1251                 m->m_pkthdr.len += sizeof(struct ip6_frag);
 1252         } else {
 1253                 /* allocate a new mbuf for the fragment header */
 1254                 struct mbuf *mfrg;
 1255 
 1256                 MGET(mfrg, M_DONTWAIT, MT_DATA);
 1257                 if (mfrg == 0)
 1258                         return (ENOBUFS);
 1259                 mfrg->m_len = sizeof(struct ip6_frag);
 1260                 *frghdrp = mtod(mfrg, struct ip6_frag *);
 1261                 mlast->m_next = mfrg;
 1262         }
 1263 
 1264         return (0);
 1265 }
 1266 
 1267 static int
 1268 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
 1269     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
 1270     int *alwaysfragp, u_int fibnum)
 1271 {
 1272         u_int32_t mtu = 0;
 1273         int alwaysfrag = 0;
 1274         int error = 0;
 1275 
 1276         if (ro_pmtu != ro) {
 1277                 /* The first hop and the final destination may differ. */
 1278                 struct sockaddr_in6 *sa6_dst =
 1279                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
 1280                 if (ro_pmtu->ro_rt &&
 1281                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
 1282                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
 1283                         RTFREE(ro_pmtu->ro_rt);
 1284                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
 1285                 }
 1286                 if (ro_pmtu->ro_rt == NULL) {
 1287                         bzero(sa6_dst, sizeof(*sa6_dst));
 1288                         sa6_dst->sin6_family = AF_INET6;
 1289                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
 1290                         sa6_dst->sin6_addr = *dst;
 1291 
 1292                         in6_rtalloc(ro_pmtu, fibnum);
 1293                 }
 1294         }
 1295         if (ro_pmtu->ro_rt) {
 1296                 u_int32_t ifmtu;
 1297                 struct in_conninfo inc;
 1298 
 1299                 bzero(&inc, sizeof(inc));
 1300                 inc.inc_flags |= INC_ISIPV6;
 1301                 inc.inc6_faddr = *dst;
 1302 
 1303                 if (ifp == NULL)
 1304                         ifp = ro_pmtu->ro_rt->rt_ifp;
 1305                 ifmtu = IN6_LINKMTU(ifp);
 1306                 mtu = tcp_hc_getmtu(&inc);
 1307                 if (mtu)
 1308                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
 1309                 else
 1310                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
 1311                 if (mtu == 0)
 1312                         mtu = ifmtu;
 1313                 else if (mtu < IPV6_MMTU) {
 1314                         /*
 1315                          * RFC2460 section 5, last paragraph:
 1316                          * if we record ICMPv6 too big message with
 1317                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
 1318                          * or smaller, with framgent header attached.
 1319                          * (fragment header is needed regardless from the
 1320                          * packet size, for translators to identify packets)
 1321                          */
 1322                         alwaysfrag = 1;
 1323                         mtu = IPV6_MMTU;
 1324                 } else if (mtu > ifmtu) {
 1325                         /*
 1326                          * The MTU on the route is larger than the MTU on
 1327                          * the interface!  This shouldn't happen, unless the
 1328                          * MTU of the interface has been changed after the
 1329                          * interface was brought up.  Change the MTU in the
 1330                          * route to match the interface MTU (as long as the
 1331                          * field isn't locked).
 1332                          */
 1333                         mtu = ifmtu;
 1334                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
 1335                 }
 1336         } else if (ifp) {
 1337                 mtu = IN6_LINKMTU(ifp);
 1338         } else
 1339                 error = EHOSTUNREACH; /* XXX */
 1340 
 1341         *mtup = mtu;
 1342         if (alwaysfragp)
 1343                 *alwaysfragp = alwaysfrag;
 1344         return (error);
 1345 }
 1346 
 1347 /*
 1348  * IP6 socket option processing.
 1349  */
 1350 int
 1351 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
 1352 {
 1353         int optdatalen, uproto;
 1354         void *optdata;
 1355         struct inpcb *in6p = sotoinpcb(so);
 1356         int error, optval;
 1357         int level, op, optname;
 1358         int optlen;
 1359         struct thread *td;
 1360 
 1361         level = sopt->sopt_level;
 1362         op = sopt->sopt_dir;
 1363         optname = sopt->sopt_name;
 1364         optlen = sopt->sopt_valsize;
 1365         td = sopt->sopt_td;
 1366         error = 0;
 1367         optval = 0;
 1368         uproto = (int)so->so_proto->pr_protocol;
 1369 
 1370         if (level != IPPROTO_IPV6) {
 1371                 error = EINVAL;
 1372 
 1373                 if (sopt->sopt_level == SOL_SOCKET &&
 1374                     sopt->sopt_dir == SOPT_SET) {
 1375                         switch (sopt->sopt_name) {
 1376                         case SO_SETFIB:
 1377                                 INP_WLOCK(in6p);
 1378                                 in6p->inp_inc.inc_fibnum = so->so_fibnum;
 1379                                 INP_WUNLOCK(in6p);
 1380                                 error = 0;
 1381                                 break;
 1382                         default:
 1383                                 break;
 1384                         }
 1385                 }
 1386         } else {
 1387                 switch (op) {
 1388 
 1389                 case SOPT_SET:
 1390                         switch (optname) {
 1391                         case IPV6_2292PKTOPTIONS:
 1392 #ifdef IPV6_PKTOPTIONS
 1393                         case IPV6_PKTOPTIONS:
 1394 #endif
 1395                         {
 1396                                 struct mbuf *m;
 1397 
 1398                                 error = soopt_getm(sopt, &m); /* XXX */
 1399                                 if (error != 0)
 1400                                         break;
 1401                                 error = soopt_mcopyin(sopt, m); /* XXX */
 1402                                 if (error != 0)
 1403                                         break;
 1404                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
 1405                                                     m, so, sopt);
 1406                                 m_freem(m); /* XXX */
 1407                                 break;
 1408                         }
 1409 
 1410                         /*
 1411                          * Use of some Hop-by-Hop options or some
 1412                          * Destination options, might require special
 1413                          * privilege.  That is, normal applications
 1414                          * (without special privilege) might be forbidden
 1415                          * from setting certain options in outgoing packets,
 1416                          * and might never see certain options in received
 1417                          * packets. [RFC 2292 Section 6]
 1418                          * KAME specific note:
 1419                          *  KAME prevents non-privileged users from sending or
 1420                          *  receiving ANY hbh/dst options in order to avoid
 1421                          *  overhead of parsing options in the kernel.
 1422                          */
 1423                         case IPV6_RECVHOPOPTS:
 1424                         case IPV6_RECVDSTOPTS:
 1425                         case IPV6_RECVRTHDRDSTOPTS:
 1426                                 if (td != NULL) {
 1427                                         error = priv_check(td,
 1428                                             PRIV_NETINET_SETHDROPTS);
 1429                                         if (error)
 1430                                                 break;
 1431                                 }
 1432                                 /* FALLTHROUGH */
 1433                         case IPV6_UNICAST_HOPS:
 1434                         case IPV6_HOPLIMIT:
 1435                         case IPV6_FAITH:
 1436 
 1437                         case IPV6_RECVPKTINFO:
 1438                         case IPV6_RECVHOPLIMIT:
 1439                         case IPV6_RECVRTHDR:
 1440                         case IPV6_RECVPATHMTU:
 1441                         case IPV6_RECVTCLASS:
 1442                         case IPV6_V6ONLY:
 1443                         case IPV6_AUTOFLOWLABEL:
 1444                         case IPV6_BINDANY:
 1445                                 if (optname == IPV6_BINDANY && td != NULL) {
 1446                                         error = priv_check(td,
 1447                                             PRIV_NETINET_BINDANY);
 1448                                         if (error)
 1449                                                 break;
 1450                                 }
 1451 
 1452                                 if (optlen != sizeof(int)) {
 1453                                         error = EINVAL;
 1454                                         break;
 1455                                 }
 1456                                 error = sooptcopyin(sopt, &optval,
 1457                                         sizeof optval, sizeof optval);
 1458                                 if (error)
 1459                                         break;
 1460                                 switch (optname) {
 1461 
 1462                                 case IPV6_UNICAST_HOPS:
 1463                                         if (optval < -1 || optval >= 256)
 1464                                                 error = EINVAL;
 1465                                         else {
 1466                                                 /* -1 = kernel default */
 1467                                                 in6p->in6p_hops = optval;
 1468                                                 if ((in6p->inp_vflag &
 1469                                                      INP_IPV4) != 0)
 1470                                                         in6p->inp_ip_ttl = optval;
 1471                                         }
 1472                                         break;
 1473 #define OPTSET(bit) \
 1474 do { \
 1475         INP_WLOCK(in6p); \
 1476         if (optval) \
 1477                 in6p->inp_flags |= (bit); \
 1478         else \
 1479                 in6p->inp_flags &= ~(bit); \
 1480         INP_WUNLOCK(in6p); \
 1481 } while (/*CONSTCOND*/ 0)
 1482 #define OPTSET2292(bit) \
 1483 do { \
 1484         INP_WLOCK(in6p); \
 1485         in6p->inp_flags |= IN6P_RFC2292; \
 1486         if (optval) \
 1487                 in6p->inp_flags |= (bit); \
 1488         else \
 1489                 in6p->inp_flags &= ~(bit); \
 1490         INP_WUNLOCK(in6p); \
 1491 } while (/*CONSTCOND*/ 0)
 1492 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
 1493 
 1494                                 case IPV6_RECVPKTINFO:
 1495                                         /* cannot mix with RFC2292 */
 1496                                         if (OPTBIT(IN6P_RFC2292)) {
 1497                                                 error = EINVAL;
 1498                                                 break;
 1499                                         }
 1500                                         OPTSET(IN6P_PKTINFO);
 1501                                         break;
 1502 
 1503                                 case IPV6_HOPLIMIT:
 1504                                 {
 1505                                         struct ip6_pktopts **optp;
 1506 
 1507                                         /* cannot mix with RFC2292 */
 1508                                         if (OPTBIT(IN6P_RFC2292)) {
 1509                                                 error = EINVAL;
 1510                                                 break;
 1511                                         }
 1512                                         optp = &in6p->in6p_outputopts;
 1513                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
 1514                                             (u_char *)&optval, sizeof(optval),
 1515                                             optp, (td != NULL) ? td->td_ucred :
 1516                                             NULL, uproto);
 1517                                         break;
 1518                                 }
 1519 
 1520                                 case IPV6_RECVHOPLIMIT:
 1521                                         /* cannot mix with RFC2292 */
 1522                                         if (OPTBIT(IN6P_RFC2292)) {
 1523                                                 error = EINVAL;
 1524                                                 break;
 1525                                         }
 1526                                         OPTSET(IN6P_HOPLIMIT);
 1527                                         break;
 1528 
 1529                                 case IPV6_RECVHOPOPTS:
 1530                                         /* cannot mix with RFC2292 */
 1531                                         if (OPTBIT(IN6P_RFC2292)) {
 1532                                                 error = EINVAL;
 1533                                                 break;
 1534                                         }
 1535                                         OPTSET(IN6P_HOPOPTS);
 1536                                         break;
 1537 
 1538                                 case IPV6_RECVDSTOPTS:
 1539                                         /* cannot mix with RFC2292 */
 1540                                         if (OPTBIT(IN6P_RFC2292)) {
 1541                                                 error = EINVAL;
 1542                                                 break;
 1543                                         }
 1544                                         OPTSET(IN6P_DSTOPTS);
 1545                                         break;
 1546 
 1547                                 case IPV6_RECVRTHDRDSTOPTS:
 1548                                         /* cannot mix with RFC2292 */
 1549                                         if (OPTBIT(IN6P_RFC2292)) {
 1550                                                 error = EINVAL;
 1551                                                 break;
 1552                                         }
 1553                                         OPTSET(IN6P_RTHDRDSTOPTS);
 1554                                         break;
 1555 
 1556                                 case IPV6_RECVRTHDR:
 1557                                         /* cannot mix with RFC2292 */
 1558                                         if (OPTBIT(IN6P_RFC2292)) {
 1559                                                 error = EINVAL;
 1560                                                 break;
 1561                                         }
 1562                                         OPTSET(IN6P_RTHDR);
 1563                                         break;
 1564 
 1565                                 case IPV6_FAITH:
 1566                                         OPTSET(INP_FAITH);
 1567                                         break;
 1568 
 1569                                 case IPV6_RECVPATHMTU:
 1570                                         /*
 1571                                          * We ignore this option for TCP
 1572                                          * sockets.
 1573                                          * (RFC3542 leaves this case
 1574                                          * unspecified.)
 1575                                          */
 1576                                         if (uproto != IPPROTO_TCP)
 1577                                                 OPTSET(IN6P_MTU);
 1578                                         break;
 1579 
 1580                                 case IPV6_V6ONLY:
 1581                                         /*
 1582                                          * make setsockopt(IPV6_V6ONLY)
 1583                                          * available only prior to bind(2).
 1584                                          * see ipng mailing list, Jun 22 2001.
 1585                                          */
 1586                                         if (in6p->inp_lport ||
 1587                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
 1588                                                 error = EINVAL;
 1589                                                 break;
 1590                                         }
 1591                                         OPTSET(IN6P_IPV6_V6ONLY);
 1592                                         if (optval)
 1593                                                 in6p->inp_vflag &= ~INP_IPV4;
 1594                                         else
 1595                                                 in6p->inp_vflag |= INP_IPV4;
 1596                                         break;
 1597                                 case IPV6_RECVTCLASS:
 1598                                         /* cannot mix with RFC2292 XXX */
 1599                                         if (OPTBIT(IN6P_RFC2292)) {
 1600                                                 error = EINVAL;
 1601                                                 break;
 1602                                         }
 1603                                         OPTSET(IN6P_TCLASS);
 1604                                         break;
 1605                                 case IPV6_AUTOFLOWLABEL:
 1606                                         OPTSET(IN6P_AUTOFLOWLABEL);
 1607                                         break;
 1608 
 1609                                 case IPV6_BINDANY:
 1610                                         OPTSET(INP_BINDANY);
 1611                                         break;
 1612                                 }
 1613                                 break;
 1614 
 1615                         case IPV6_TCLASS:
 1616                         case IPV6_DONTFRAG:
 1617                         case IPV6_USE_MIN_MTU:
 1618                         case IPV6_PREFER_TEMPADDR:
 1619                                 if (optlen != sizeof(optval)) {
 1620                                         error = EINVAL;
 1621                                         break;
 1622                                 }
 1623                                 error = sooptcopyin(sopt, &optval,
 1624                                         sizeof optval, sizeof optval);
 1625                                 if (error)
 1626                                         break;
 1627                                 {
 1628                                         struct ip6_pktopts **optp;
 1629                                         optp = &in6p->in6p_outputopts;
 1630                                         error = ip6_pcbopt(optname,
 1631                                             (u_char *)&optval, sizeof(optval),
 1632                                             optp, (td != NULL) ? td->td_ucred :
 1633                                             NULL, uproto);
 1634                                         break;
 1635                                 }
 1636 
 1637                         case IPV6_2292PKTINFO:
 1638                         case IPV6_2292HOPLIMIT:
 1639                         case IPV6_2292HOPOPTS:
 1640                         case IPV6_2292DSTOPTS:
 1641                         case IPV6_2292RTHDR:
 1642                                 /* RFC 2292 */
 1643                                 if (optlen != sizeof(int)) {
 1644                                         error = EINVAL;
 1645                                         break;
 1646                                 }
 1647                                 error = sooptcopyin(sopt, &optval,
 1648                                         sizeof optval, sizeof optval);
 1649                                 if (error)
 1650                                         break;
 1651                                 switch (optname) {
 1652                                 case IPV6_2292PKTINFO:
 1653                                         OPTSET2292(IN6P_PKTINFO);
 1654                                         break;
 1655                                 case IPV6_2292HOPLIMIT:
 1656                                         OPTSET2292(IN6P_HOPLIMIT);
 1657                                         break;
 1658                                 case IPV6_2292HOPOPTS:
 1659                                         /*
 1660                                          * Check super-user privilege.
 1661                                          * See comments for IPV6_RECVHOPOPTS.
 1662                                          */
 1663                                         if (td != NULL) {
 1664                                                 error = priv_check(td,
 1665                                                     PRIV_NETINET_SETHDROPTS);
 1666                                                 if (error)
 1667                                                         return (error);
 1668                                         }
 1669                                         OPTSET2292(IN6P_HOPOPTS);
 1670                                         break;
 1671                                 case IPV6_2292DSTOPTS:
 1672                                         if (td != NULL) {
 1673                                                 error = priv_check(td,
 1674                                                     PRIV_NETINET_SETHDROPTS);
 1675                                                 if (error)
 1676                                                         return (error);
 1677                                         }
 1678                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
 1679                                         break;
 1680                                 case IPV6_2292RTHDR:
 1681                                         OPTSET2292(IN6P_RTHDR);
 1682                                         break;
 1683                                 }
 1684                                 break;
 1685                         case IPV6_PKTINFO:
 1686                         case IPV6_HOPOPTS:
 1687                         case IPV6_RTHDR:
 1688                         case IPV6_DSTOPTS:
 1689                         case IPV6_RTHDRDSTOPTS:
 1690                         case IPV6_NEXTHOP:
 1691                         {
 1692                                 /* new advanced API (RFC3542) */
 1693                                 u_char *optbuf;
 1694                                 u_char optbuf_storage[MCLBYTES];
 1695                                 int optlen;
 1696                                 struct ip6_pktopts **optp;
 1697 
 1698                                 /* cannot mix with RFC2292 */
 1699                                 if (OPTBIT(IN6P_RFC2292)) {
 1700                                         error = EINVAL;
 1701                                         break;
 1702                                 }
 1703 
 1704                                 /*
 1705                                  * We only ensure valsize is not too large
 1706                                  * here.  Further validation will be done
 1707                                  * later.
 1708                                  */
 1709                                 error = sooptcopyin(sopt, optbuf_storage,
 1710                                     sizeof(optbuf_storage), 0);
 1711                                 if (error)
 1712                                         break;
 1713                                 optlen = sopt->sopt_valsize;
 1714                                 optbuf = optbuf_storage;
 1715                                 optp = &in6p->in6p_outputopts;
 1716                                 error = ip6_pcbopt(optname, optbuf, optlen,
 1717                                     optp, (td != NULL) ? td->td_ucred : NULL,
 1718                                     uproto);
 1719                                 break;
 1720                         }
 1721 #undef OPTSET
 1722 
 1723                         case IPV6_MULTICAST_IF:
 1724                         case IPV6_MULTICAST_HOPS:
 1725                         case IPV6_MULTICAST_LOOP:
 1726                         case IPV6_JOIN_GROUP:
 1727                         case IPV6_LEAVE_GROUP:
 1728                         case IPV6_MSFILTER:
 1729                         case MCAST_BLOCK_SOURCE:
 1730                         case MCAST_UNBLOCK_SOURCE:
 1731                         case MCAST_JOIN_GROUP:
 1732                         case MCAST_LEAVE_GROUP:
 1733                         case MCAST_JOIN_SOURCE_GROUP:
 1734                         case MCAST_LEAVE_SOURCE_GROUP:
 1735                                 error = ip6_setmoptions(in6p, sopt);
 1736                                 break;
 1737 
 1738                         case IPV6_PORTRANGE:
 1739                                 error = sooptcopyin(sopt, &optval,
 1740                                     sizeof optval, sizeof optval);
 1741                                 if (error)
 1742                                         break;
 1743 
 1744                                 INP_WLOCK(in6p);
 1745                                 switch (optval) {
 1746                                 case IPV6_PORTRANGE_DEFAULT:
 1747                                         in6p->inp_flags &= ~(INP_LOWPORT);
 1748                                         in6p->inp_flags &= ~(INP_HIGHPORT);
 1749                                         break;
 1750 
 1751                                 case IPV6_PORTRANGE_HIGH:
 1752                                         in6p->inp_flags &= ~(INP_LOWPORT);
 1753                                         in6p->inp_flags |= INP_HIGHPORT;
 1754                                         break;
 1755 
 1756                                 case IPV6_PORTRANGE_LOW:
 1757                                         in6p->inp_flags &= ~(INP_HIGHPORT);
 1758                                         in6p->inp_flags |= INP_LOWPORT;
 1759                                         break;
 1760 
 1761                                 default:
 1762                                         error = EINVAL;
 1763                                         break;
 1764                                 }
 1765                                 INP_WUNLOCK(in6p);
 1766                                 break;
 1767 
 1768 #ifdef IPSEC
 1769                         case IPV6_IPSEC_POLICY:
 1770                         {
 1771                                 caddr_t req;
 1772                                 struct mbuf *m;
 1773 
 1774                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
 1775                                         break;
 1776                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
 1777                                         break;
 1778                                 req = mtod(m, caddr_t);
 1779                                 error = ipsec_set_policy(in6p, optname, req,
 1780                                     m->m_len, (sopt->sopt_td != NULL) ?
 1781                                     sopt->sopt_td->td_ucred : NULL);
 1782                                 m_freem(m);
 1783                                 break;
 1784                         }
 1785 #endif /* IPSEC */
 1786 
 1787                         default:
 1788                                 error = ENOPROTOOPT;
 1789                                 break;
 1790                         }
 1791                         break;
 1792 
 1793                 case SOPT_GET:
 1794                         switch (optname) {
 1795 
 1796                         case IPV6_2292PKTOPTIONS:
 1797 #ifdef IPV6_PKTOPTIONS
 1798                         case IPV6_PKTOPTIONS:
 1799 #endif
 1800                                 /*
 1801                                  * RFC3542 (effectively) deprecated the
 1802                                  * semantics of the 2292-style pktoptions.
 1803                                  * Since it was not reliable in nature (i.e.,
 1804                                  * applications had to expect the lack of some
 1805                                  * information after all), it would make sense
 1806                                  * to simplify this part by always returning
 1807                                  * empty data.
 1808                                  */
 1809                                 sopt->sopt_valsize = 0;
 1810                                 break;
 1811 
 1812                         case IPV6_RECVHOPOPTS:
 1813                         case IPV6_RECVDSTOPTS:
 1814                         case IPV6_RECVRTHDRDSTOPTS:
 1815                         case IPV6_UNICAST_HOPS:
 1816                         case IPV6_RECVPKTINFO:
 1817                         case IPV6_RECVHOPLIMIT:
 1818                         case IPV6_RECVRTHDR:
 1819                         case IPV6_RECVPATHMTU:
 1820 
 1821                         case IPV6_FAITH:
 1822                         case IPV6_V6ONLY:
 1823                         case IPV6_PORTRANGE:
 1824                         case IPV6_RECVTCLASS:
 1825                         case IPV6_AUTOFLOWLABEL:
 1826                         case IPV6_BINDANY:
 1827                                 switch (optname) {
 1828 
 1829                                 case IPV6_RECVHOPOPTS:
 1830                                         optval = OPTBIT(IN6P_HOPOPTS);
 1831                                         break;
 1832 
 1833                                 case IPV6_RECVDSTOPTS:
 1834                                         optval = OPTBIT(IN6P_DSTOPTS);
 1835                                         break;
 1836 
 1837                                 case IPV6_RECVRTHDRDSTOPTS:
 1838                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
 1839                                         break;
 1840 
 1841                                 case IPV6_UNICAST_HOPS:
 1842                                         optval = in6p->in6p_hops;
 1843                                         break;
 1844 
 1845                                 case IPV6_RECVPKTINFO:
 1846                                         optval = OPTBIT(IN6P_PKTINFO);
 1847                                         break;
 1848 
 1849                                 case IPV6_RECVHOPLIMIT:
 1850                                         optval = OPTBIT(IN6P_HOPLIMIT);
 1851                                         break;
 1852 
 1853                                 case IPV6_RECVRTHDR:
 1854                                         optval = OPTBIT(IN6P_RTHDR);
 1855                                         break;
 1856 
 1857                                 case IPV6_RECVPATHMTU:
 1858                                         optval = OPTBIT(IN6P_MTU);
 1859                                         break;
 1860 
 1861                                 case IPV6_FAITH:
 1862                                         optval = OPTBIT(INP_FAITH);
 1863                                         break;
 1864 
 1865                                 case IPV6_V6ONLY:
 1866                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
 1867                                         break;
 1868 
 1869                                 case IPV6_PORTRANGE:
 1870                                     {
 1871                                         int flags;
 1872                                         flags = in6p->inp_flags;
 1873                                         if (flags & INP_HIGHPORT)
 1874                                                 optval = IPV6_PORTRANGE_HIGH;
 1875                                         else if (flags & INP_LOWPORT)
 1876                                                 optval = IPV6_PORTRANGE_LOW;
 1877                                         else
 1878                                                 optval = 0;
 1879                                         break;
 1880                                     }
 1881                                 case IPV6_RECVTCLASS:
 1882                                         optval = OPTBIT(IN6P_TCLASS);
 1883                                         break;
 1884 
 1885                                 case IPV6_AUTOFLOWLABEL:
 1886                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
 1887                                         break;
 1888 
 1889                                 case IPV6_BINDANY:
 1890                                         optval = OPTBIT(INP_BINDANY);
 1891                                         break;
 1892                                 }
 1893                                 if (error)
 1894                                         break;
 1895                                 error = sooptcopyout(sopt, &optval,
 1896                                         sizeof optval);
 1897                                 break;
 1898 
 1899                         case IPV6_PATHMTU:
 1900                         {
 1901                                 u_long pmtu = 0;
 1902                                 struct ip6_mtuinfo mtuinfo;
 1903                                 struct route_in6 sro;
 1904 
 1905                                 bzero(&sro, sizeof(sro));
 1906 
 1907                                 if (!(so->so_state & SS_ISCONNECTED))
 1908                                         return (ENOTCONN);
 1909                                 /*
 1910                                  * XXX: we dot not consider the case of source
 1911                                  * routing, or optional information to specify
 1912                                  * the outgoing interface.
 1913                                  */
 1914                                 error = ip6_getpmtu(&sro, NULL, NULL,
 1915                                     &in6p->in6p_faddr, &pmtu, NULL,
 1916                                     so->so_fibnum);
 1917                                 if (sro.ro_rt)
 1918                                         RTFREE(sro.ro_rt);
 1919                                 if (error)
 1920                                         break;
 1921                                 if (pmtu > IPV6_MAXPACKET)
 1922                                         pmtu = IPV6_MAXPACKET;
 1923 
 1924                                 bzero(&mtuinfo, sizeof(mtuinfo));
 1925                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
 1926                                 optdata = (void *)&mtuinfo;
 1927                                 optdatalen = sizeof(mtuinfo);
 1928                                 error = sooptcopyout(sopt, optdata,
 1929                                     optdatalen);
 1930                                 break;
 1931                         }
 1932 
 1933                         case IPV6_2292PKTINFO:
 1934                         case IPV6_2292HOPLIMIT:
 1935                         case IPV6_2292HOPOPTS:
 1936                         case IPV6_2292RTHDR:
 1937                         case IPV6_2292DSTOPTS:
 1938                                 switch (optname) {
 1939                                 case IPV6_2292PKTINFO:
 1940                                         optval = OPTBIT(IN6P_PKTINFO);
 1941                                         break;
 1942                                 case IPV6_2292HOPLIMIT:
 1943                                         optval = OPTBIT(IN6P_HOPLIMIT);
 1944                                         break;
 1945                                 case IPV6_2292HOPOPTS:
 1946                                         optval = OPTBIT(IN6P_HOPOPTS);
 1947                                         break;
 1948                                 case IPV6_2292RTHDR:
 1949                                         optval = OPTBIT(IN6P_RTHDR);
 1950                                         break;
 1951                                 case IPV6_2292DSTOPTS:
 1952                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
 1953                                         break;
 1954                                 }
 1955                                 error = sooptcopyout(sopt, &optval,
 1956                                     sizeof optval);
 1957                                 break;
 1958                         case IPV6_PKTINFO:
 1959                         case IPV6_HOPOPTS:
 1960                         case IPV6_RTHDR:
 1961                         case IPV6_DSTOPTS:
 1962                         case IPV6_RTHDRDSTOPTS:
 1963                         case IPV6_NEXTHOP:
 1964                         case IPV6_TCLASS:
 1965                         case IPV6_DONTFRAG:
 1966                         case IPV6_USE_MIN_MTU:
 1967                         case IPV6_PREFER_TEMPADDR:
 1968                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
 1969                                     optname, sopt);
 1970                                 break;
 1971 
 1972                         case IPV6_MULTICAST_IF:
 1973                         case IPV6_MULTICAST_HOPS:
 1974                         case IPV6_MULTICAST_LOOP:
 1975                         case IPV6_MSFILTER:
 1976                                 error = ip6_getmoptions(in6p, sopt);
 1977                                 break;
 1978 
 1979 #ifdef IPSEC
 1980                         case IPV6_IPSEC_POLICY:
 1981                           {
 1982                                 caddr_t req = NULL;
 1983                                 size_t len = 0;
 1984                                 struct mbuf *m = NULL;
 1985                                 struct mbuf **mp = &m;
 1986                                 size_t ovalsize = sopt->sopt_valsize;
 1987                                 caddr_t oval = (caddr_t)sopt->sopt_val;
 1988 
 1989                                 error = soopt_getm(sopt, &m); /* XXX */
 1990                                 if (error != 0)
 1991                                         break;
 1992                                 error = soopt_mcopyin(sopt, m); /* XXX */
 1993                                 if (error != 0)
 1994                                         break;
 1995                                 sopt->sopt_valsize = ovalsize;
 1996                                 sopt->sopt_val = oval;
 1997                                 if (m) {
 1998                                         req = mtod(m, caddr_t);
 1999                                         len = m->m_len;
 2000                                 }
 2001                                 error = ipsec_get_policy(in6p, req, len, mp);
 2002                                 if (error == 0)
 2003                                         error = soopt_mcopyout(sopt, m); /* XXX */
 2004                                 if (error == 0 && m)
 2005                                         m_freem(m);
 2006                                 break;
 2007                           }
 2008 #endif /* IPSEC */
 2009 
 2010                         default:
 2011                                 error = ENOPROTOOPT;
 2012                                 break;
 2013                         }
 2014                         break;
 2015                 }
 2016         }
 2017         return (error);
 2018 }
 2019 
 2020 int
 2021 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
 2022 {
 2023         int error = 0, optval, optlen;
 2024         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
 2025         struct inpcb *in6p = sotoinpcb(so);
 2026         int level, op, optname;
 2027 
 2028         level = sopt->sopt_level;
 2029         op = sopt->sopt_dir;
 2030         optname = sopt->sopt_name;
 2031         optlen = sopt->sopt_valsize;
 2032 
 2033         if (level != IPPROTO_IPV6) {
 2034                 return (EINVAL);
 2035         }
 2036 
 2037         switch (optname) {
 2038         case IPV6_CHECKSUM:
 2039                 /*
 2040                  * For ICMPv6 sockets, no modification allowed for checksum
 2041                  * offset, permit "no change" values to help existing apps.
 2042                  *
 2043                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
 2044                  * for an ICMPv6 socket will fail."
 2045                  * The current behavior does not meet RFC3542.
 2046                  */
 2047                 switch (op) {
 2048                 case SOPT_SET:
 2049                         if (optlen != sizeof(int)) {
 2050                                 error = EINVAL;
 2051                                 break;
 2052                         }
 2053                         error = sooptcopyin(sopt, &optval, sizeof(optval),
 2054                                             sizeof(optval));
 2055                         if (error)
 2056                                 break;
 2057                         if ((optval % 2) != 0) {
 2058                                 /* the API assumes even offset values */
 2059                                 error = EINVAL;
 2060                         } else if (so->so_proto->pr_protocol ==
 2061                             IPPROTO_ICMPV6) {
 2062                                 if (optval != icmp6off)
 2063                                         error = EINVAL;
 2064                         } else
 2065                                 in6p->in6p_cksum = optval;
 2066                         break;
 2067 
 2068                 case SOPT_GET:
 2069                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
 2070                                 optval = icmp6off;
 2071                         else
 2072                                 optval = in6p->in6p_cksum;
 2073 
 2074                         error = sooptcopyout(sopt, &optval, sizeof(optval));
 2075                         break;
 2076 
 2077                 default:
 2078                         error = EINVAL;
 2079                         break;
 2080                 }
 2081                 break;
 2082 
 2083         default:
 2084                 error = ENOPROTOOPT;
 2085                 break;
 2086         }
 2087 
 2088         return (error);
 2089 }
 2090 
 2091 /*
 2092  * Set up IP6 options in pcb for insertion in output packets or
 2093  * specifying behavior of outgoing packets.
 2094  */
 2095 static int
 2096 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
 2097     struct socket *so, struct sockopt *sopt)
 2098 {
 2099         struct ip6_pktopts *opt = *pktopt;
 2100         int error = 0;
 2101         struct thread *td = sopt->sopt_td;
 2102 
 2103         /* turn off any old options. */
 2104         if (opt) {
 2105 #ifdef DIAGNOSTIC
 2106                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
 2107                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
 2108                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
 2109                         printf("ip6_pcbopts: all specified options are cleared.\n");
 2110 #endif
 2111                 ip6_clearpktopts(opt, -1);
 2112         } else
 2113                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
 2114         *pktopt = NULL;
 2115 
 2116         if (!m || m->m_len == 0) {
 2117                 /*
 2118                  * Only turning off any previous options, regardless of
 2119                  * whether the opt is just created or given.
 2120                  */
 2121                 free(opt, M_IP6OPT);
 2122                 return (0);
 2123         }
 2124 
 2125         /*  set options specified by user. */
 2126         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
 2127             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
 2128                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
 2129                 free(opt, M_IP6OPT);
 2130                 return (error);
 2131         }
 2132         *pktopt = opt;
 2133         return (0);
 2134 }
 2135 
 2136 /*
 2137  * initialize ip6_pktopts.  beware that there are non-zero default values in
 2138  * the struct.
 2139  */
 2140 void
 2141 ip6_initpktopts(struct ip6_pktopts *opt)
 2142 {
 2143 
 2144         bzero(opt, sizeof(*opt));
 2145         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
 2146         opt->ip6po_tclass = -1; /* -1 means default traffic class */
 2147         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
 2148         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
 2149 }
 2150 
 2151 static int
 2152 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
 2153     struct ucred *cred, int uproto)
 2154 {
 2155         struct ip6_pktopts *opt;
 2156 
 2157         if (*pktopt == NULL) {
 2158                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
 2159                     M_WAITOK);
 2160                 ip6_initpktopts(*pktopt);
 2161         }
 2162         opt = *pktopt;
 2163 
 2164         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
 2165 }
 2166 
 2167 static int
 2168 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
 2169 {
 2170         void *optdata = NULL;
 2171         int optdatalen = 0;
 2172         struct ip6_ext *ip6e;
 2173         int error = 0;
 2174         struct in6_pktinfo null_pktinfo;
 2175         int deftclass = 0, on;
 2176         int defminmtu = IP6PO_MINMTU_MCASTONLY;
 2177         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
 2178 
 2179         switch (optname) {
 2180         case IPV6_PKTINFO:
 2181                 if (pktopt && pktopt->ip6po_pktinfo)
 2182                         optdata = (void *)pktopt->ip6po_pktinfo;
 2183                 else {
 2184                         /* XXX: we don't have to do this every time... */
 2185                         bzero(&null_pktinfo, sizeof(null_pktinfo));
 2186                         optdata = (void *)&null_pktinfo;
 2187                 }
 2188                 optdatalen = sizeof(struct in6_pktinfo);
 2189                 break;
 2190         case IPV6_TCLASS:
 2191                 if (pktopt && pktopt->ip6po_tclass >= 0)
 2192                         optdata = (void *)&pktopt->ip6po_tclass;
 2193                 else
 2194                         optdata = (void *)&deftclass;
 2195                 optdatalen = sizeof(int);
 2196                 break;
 2197         case IPV6_HOPOPTS:
 2198                 if (pktopt && pktopt->ip6po_hbh) {
 2199                         optdata = (void *)pktopt->ip6po_hbh;
 2200                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
 2201                         optdatalen = (ip6e->ip6e_len + 1) << 3;
 2202                 }
 2203                 break;
 2204         case IPV6_RTHDR:
 2205                 if (pktopt && pktopt->ip6po_rthdr) {
 2206                         optdata = (void *)pktopt->ip6po_rthdr;
 2207                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
 2208                         optdatalen = (ip6e->ip6e_len + 1) << 3;
 2209                 }
 2210                 break;
 2211         case IPV6_RTHDRDSTOPTS:
 2212                 if (pktopt && pktopt->ip6po_dest1) {
 2213                         optdata = (void *)pktopt->ip6po_dest1;
 2214                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
 2215                         optdatalen = (ip6e->ip6e_len + 1) << 3;
 2216                 }
 2217                 break;
 2218         case IPV6_DSTOPTS:
 2219                 if (pktopt && pktopt->ip6po_dest2) {
 2220                         optdata = (void *)pktopt->ip6po_dest2;
 2221                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
 2222                         optdatalen = (ip6e->ip6e_len + 1) << 3;
 2223                 }
 2224                 break;
 2225         case IPV6_NEXTHOP:
 2226                 if (pktopt && pktopt->ip6po_nexthop) {
 2227                         optdata = (void *)pktopt->ip6po_nexthop;
 2228                         optdatalen = pktopt->ip6po_nexthop->sa_len;
 2229                 }
 2230                 break;
 2231         case IPV6_USE_MIN_MTU:
 2232                 if (pktopt)
 2233                         optdata = (void *)&pktopt->ip6po_minmtu;
 2234                 else
 2235                         optdata = (void *)&defminmtu;
 2236                 optdatalen = sizeof(int);
 2237                 break;
 2238         case IPV6_DONTFRAG:
 2239                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
 2240                         on = 1;
 2241                 else
 2242                         on = 0;
 2243                 optdata = (void *)&on;
 2244                 optdatalen = sizeof(on);
 2245                 break;
 2246         case IPV6_PREFER_TEMPADDR:
 2247                 if (pktopt)
 2248                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
 2249                 else
 2250                         optdata = (void *)&defpreftemp;
 2251                 optdatalen = sizeof(int);
 2252                 break;
 2253         default:                /* should not happen */
 2254 #ifdef DIAGNOSTIC
 2255                 panic("ip6_getpcbopt: unexpected option\n");
 2256 #endif
 2257                 return (ENOPROTOOPT);
 2258         }
 2259 
 2260         error = sooptcopyout(sopt, optdata, optdatalen);
 2261 
 2262         return (error);
 2263 }
 2264 
 2265 void
 2266 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
 2267 {
 2268         if (pktopt == NULL)
 2269                 return;
 2270 
 2271         if (optname == -1 || optname == IPV6_PKTINFO) {
 2272                 if (pktopt->ip6po_pktinfo)
 2273                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
 2274                 pktopt->ip6po_pktinfo = NULL;
 2275         }
 2276         if (optname == -1 || optname == IPV6_HOPLIMIT)
 2277                 pktopt->ip6po_hlim = -1;
 2278         if (optname == -1 || optname == IPV6_TCLASS)
 2279                 pktopt->ip6po_tclass = -1;
 2280         if (optname == -1 || optname == IPV6_NEXTHOP) {
 2281                 if (pktopt->ip6po_nextroute.ro_rt) {
 2282                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
 2283                         pktopt->ip6po_nextroute.ro_rt = NULL;
 2284                 }
 2285                 if (pktopt->ip6po_nexthop)
 2286                         free(pktopt->ip6po_nexthop, M_IP6OPT);
 2287                 pktopt->ip6po_nexthop = NULL;
 2288         }
 2289         if (optname == -1 || optname == IPV6_HOPOPTS) {
 2290                 if (pktopt->ip6po_hbh)
 2291                         free(pktopt->ip6po_hbh, M_IP6OPT);
 2292                 pktopt->ip6po_hbh = NULL;
 2293         }
 2294         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
 2295                 if (pktopt->ip6po_dest1)
 2296                         free(pktopt->ip6po_dest1, M_IP6OPT);
 2297                 pktopt->ip6po_dest1 = NULL;
 2298         }
 2299         if (optname == -1 || optname == IPV6_RTHDR) {
 2300                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
 2301                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
 2302                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
 2303                 if (pktopt->ip6po_route.ro_rt) {
 2304                         RTFREE(pktopt->ip6po_route.ro_rt);
 2305                         pktopt->ip6po_route.ro_rt = NULL;
 2306                 }
 2307         }
 2308         if (optname == -1 || optname == IPV6_DSTOPTS) {
 2309                 if (pktopt->ip6po_dest2)
 2310                         free(pktopt->ip6po_dest2, M_IP6OPT);
 2311                 pktopt->ip6po_dest2 = NULL;
 2312         }
 2313 }
 2314 
 2315 #define PKTOPT_EXTHDRCPY(type) \
 2316 do {\
 2317         if (src->type) {\
 2318                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
 2319                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
 2320                 if (dst->type == NULL && canwait == M_NOWAIT)\
 2321                         goto bad;\
 2322                 bcopy(src->type, dst->type, hlen);\
 2323         }\
 2324 } while (/*CONSTCOND*/ 0)
 2325 
 2326 static int
 2327 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
 2328 {
 2329         if (dst == NULL || src == NULL)  {
 2330                 printf("ip6_clearpktopts: invalid argument\n");
 2331                 return (EINVAL);
 2332         }
 2333 
 2334         dst->ip6po_hlim = src->ip6po_hlim;
 2335         dst->ip6po_tclass = src->ip6po_tclass;
 2336         dst->ip6po_flags = src->ip6po_flags;
 2337         dst->ip6po_minmtu = src->ip6po_minmtu;
 2338         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
 2339         if (src->ip6po_pktinfo) {
 2340                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
 2341                     M_IP6OPT, canwait);
 2342                 if (dst->ip6po_pktinfo == NULL)
 2343                         goto bad;
 2344                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
 2345         }
 2346         if (src->ip6po_nexthop) {
 2347                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
 2348                     M_IP6OPT, canwait);
 2349                 if (dst->ip6po_nexthop == NULL)
 2350                         goto bad;
 2351                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
 2352                     src->ip6po_nexthop->sa_len);
 2353         }
 2354         PKTOPT_EXTHDRCPY(ip6po_hbh);
 2355         PKTOPT_EXTHDRCPY(ip6po_dest1);
 2356         PKTOPT_EXTHDRCPY(ip6po_dest2);
 2357         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
 2358         return (0);
 2359 
 2360   bad:
 2361         ip6_clearpktopts(dst, -1);
 2362         return (ENOBUFS);
 2363 }
 2364 #undef PKTOPT_EXTHDRCPY
 2365 
 2366 struct ip6_pktopts *
 2367 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
 2368 {
 2369         int error;
 2370         struct ip6_pktopts *dst;
 2371 
 2372         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
 2373         if (dst == NULL)
 2374                 return (NULL);
 2375         ip6_initpktopts(dst);
 2376 
 2377         if ((error = copypktopts(dst, src, canwait)) != 0) {
 2378                 free(dst, M_IP6OPT);
 2379                 return (NULL);
 2380         }
 2381 
 2382         return (dst);
 2383 }
 2384 
 2385 void
 2386 ip6_freepcbopts(struct ip6_pktopts *pktopt)
 2387 {
 2388         if (pktopt == NULL)
 2389                 return;
 2390 
 2391         ip6_clearpktopts(pktopt, -1);
 2392 
 2393         free(pktopt, M_IP6OPT);
 2394 }
 2395 
 2396 /*
 2397  * Set IPv6 outgoing packet options based on advanced API.
 2398  */
 2399 int
 2400 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
 2401     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
 2402 {
 2403         struct cmsghdr *cm = 0;
 2404 
 2405         if (control == NULL || opt == NULL)
 2406                 return (EINVAL);
 2407 
 2408         ip6_initpktopts(opt);
 2409         if (stickyopt) {
 2410                 int error;
 2411 
 2412                 /*
 2413                  * If stickyopt is provided, make a local copy of the options
 2414                  * for this particular packet, then override them by ancillary
 2415                  * objects.
 2416                  * XXX: copypktopts() does not copy the cached route to a next
 2417                  * hop (if any).  This is not very good in terms of efficiency,
 2418                  * but we can allow this since this option should be rarely
 2419                  * used.
 2420                  */
 2421                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
 2422                         return (error);
 2423         }
 2424 
 2425         /*
 2426          * XXX: Currently, we assume all the optional information is stored
 2427          * in a single mbuf.
 2428          */
 2429         if (control->m_next)
 2430                 return (EINVAL);
 2431 
 2432         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
 2433             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 2434                 int error;
 2435 
 2436                 if (control->m_len < CMSG_LEN(0))
 2437                         return (EINVAL);
 2438 
 2439                 cm = mtod(control, struct cmsghdr *);
 2440                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
 2441                         return (EINVAL);
 2442                 if (cm->cmsg_level != IPPROTO_IPV6)
 2443                         continue;
 2444 
 2445                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
 2446                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
 2447                 if (error)
 2448                         return (error);
 2449         }
 2450 
 2451         return (0);
 2452 }
 2453 
 2454 /*
 2455  * Set a particular packet option, as a sticky option or an ancillary data
 2456  * item.  "len" can be 0 only when it's a sticky option.
 2457  * We have 4 cases of combination of "sticky" and "cmsg":
 2458  * "sticky=0, cmsg=0": impossible
 2459  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
 2460  * "sticky=1, cmsg=0": RFC3542 socket option
 2461  * "sticky=1, cmsg=1": RFC2292 socket option
 2462  */
 2463 static int
 2464 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
 2465     struct ucred *cred, int sticky, int cmsg, int uproto)
 2466 {
 2467         int minmtupolicy, preftemp;
 2468         int error;
 2469 
 2470         if (!sticky && !cmsg) {
 2471 #ifdef DIAGNOSTIC
 2472                 printf("ip6_setpktopt: impossible case\n");
 2473 #endif
 2474                 return (EINVAL);
 2475         }
 2476 
 2477         /*
 2478          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
 2479          * not be specified in the context of RFC3542.  Conversely,
 2480          * RFC3542 types should not be specified in the context of RFC2292.
 2481          */
 2482         if (!cmsg) {
 2483                 switch (optname) {
 2484                 case IPV6_2292PKTINFO:
 2485                 case IPV6_2292HOPLIMIT:
 2486                 case IPV6_2292NEXTHOP:
 2487                 case IPV6_2292HOPOPTS:
 2488                 case IPV6_2292DSTOPTS:
 2489                 case IPV6_2292RTHDR:
 2490                 case IPV6_2292PKTOPTIONS:
 2491                         return (ENOPROTOOPT);
 2492                 }
 2493         }
 2494         if (sticky && cmsg) {
 2495                 switch (optname) {
 2496                 case IPV6_PKTINFO:
 2497                 case IPV6_HOPLIMIT:
 2498                 case IPV6_NEXTHOP:
 2499                 case IPV6_HOPOPTS:
 2500                 case IPV6_DSTOPTS:
 2501                 case IPV6_RTHDRDSTOPTS:
 2502                 case IPV6_RTHDR:
 2503                 case IPV6_USE_MIN_MTU:
 2504                 case IPV6_DONTFRAG:
 2505                 case IPV6_TCLASS:
 2506                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
 2507                         return (ENOPROTOOPT);
 2508                 }
 2509         }
 2510 
 2511         switch (optname) {
 2512         case IPV6_2292PKTINFO:
 2513         case IPV6_PKTINFO:
 2514         {
 2515                 struct ifnet *ifp = NULL;
 2516                 struct in6_pktinfo *pktinfo;
 2517 
 2518                 if (len != sizeof(struct in6_pktinfo))
 2519                         return (EINVAL);
 2520 
 2521                 pktinfo = (struct in6_pktinfo *)buf;
 2522 
 2523                 /*
 2524                  * An application can clear any sticky IPV6_PKTINFO option by
 2525                  * doing a "regular" setsockopt with ipi6_addr being
 2526                  * in6addr_any and ipi6_ifindex being zero.
 2527                  * [RFC 3542, Section 6]
 2528                  */
 2529                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
 2530                     pktinfo->ipi6_ifindex == 0 &&
 2531                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
 2532                         ip6_clearpktopts(opt, optname);
 2533                         break;
 2534                 }
 2535 
 2536                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
 2537                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
 2538                         return (EINVAL);
 2539                 }
 2540 
 2541                 /* validate the interface index if specified. */
 2542                 if (pktinfo->ipi6_ifindex > V_if_index ||
 2543                     pktinfo->ipi6_ifindex < 0) {
 2544                          return (ENXIO);
 2545                 }
 2546                 if (pktinfo->ipi6_ifindex) {
 2547                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
 2548                         if (ifp == NULL)
 2549                                 return (ENXIO);
 2550                 }
 2551 
 2552                 /*
 2553                  * We store the address anyway, and let in6_selectsrc()
 2554                  * validate the specified address.  This is because ipi6_addr
 2555                  * may not have enough information about its scope zone, and
 2556                  * we may need additional information (such as outgoing
 2557                  * interface or the scope zone of a destination address) to
 2558                  * disambiguate the scope.
 2559                  * XXX: the delay of the validation may confuse the
 2560                  * application when it is used as a sticky option.
 2561                  */
 2562                 if (opt->ip6po_pktinfo == NULL) {
 2563                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
 2564                             M_IP6OPT, M_NOWAIT);
 2565                         if (opt->ip6po_pktinfo == NULL)
 2566                                 return (ENOBUFS);
 2567                 }
 2568                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
 2569                 break;
 2570         }
 2571 
 2572         case IPV6_2292HOPLIMIT:
 2573         case IPV6_HOPLIMIT:
 2574         {
 2575                 int *hlimp;
 2576 
 2577                 /*
 2578                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
 2579                  * to simplify the ordering among hoplimit options.
 2580                  */
 2581                 if (optname == IPV6_HOPLIMIT && sticky)
 2582                         return (ENOPROTOOPT);
 2583 
 2584                 if (len != sizeof(int))
 2585                         return (EINVAL);
 2586                 hlimp = (int *)buf;
 2587                 if (*hlimp < -1 || *hlimp > 255)
 2588                         return (EINVAL);
 2589 
 2590                 opt->ip6po_hlim = *hlimp;
 2591                 break;
 2592         }
 2593 
 2594         case IPV6_TCLASS:
 2595         {
 2596                 int tclass;
 2597 
 2598                 if (len != sizeof(int))
 2599                         return (EINVAL);
 2600                 tclass = *(int *)buf;
 2601                 if (tclass < -1 || tclass > 255)
 2602                         return (EINVAL);
 2603 
 2604                 opt->ip6po_tclass = tclass;
 2605                 break;
 2606         }
 2607 
 2608         case IPV6_2292NEXTHOP:
 2609         case IPV6_NEXTHOP:
 2610                 if (cred != NULL) {
 2611                         error = priv_check_cred(cred,
 2612                             PRIV_NETINET_SETHDROPTS, 0);
 2613                         if (error)
 2614                                 return (error);
 2615                 }
 2616 
 2617                 if (len == 0) { /* just remove the option */
 2618                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
 2619                         break;
 2620                 }
 2621 
 2622                 /* check if cmsg_len is large enough for sa_len */
 2623                 if (len < sizeof(struct sockaddr) || len < *buf)
 2624                         return (EINVAL);
 2625 
 2626                 switch (((struct sockaddr *)buf)->sa_family) {
 2627                 case AF_INET6:
 2628                 {
 2629                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
 2630                         int error;
 2631 
 2632                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
 2633                                 return (EINVAL);
 2634 
 2635                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
 2636                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
 2637                                 return (EINVAL);
 2638                         }
 2639                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
 2640                             != 0) {
 2641                                 return (error);
 2642                         }
 2643                         break;
 2644                 }
 2645                 case AF_LINK:   /* should eventually be supported */
 2646                 default:
 2647                         return (EAFNOSUPPORT);
 2648                 }
 2649 
 2650                 /* turn off the previous option, then set the new option. */
 2651                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
 2652                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
 2653                 if (opt->ip6po_nexthop == NULL)
 2654                         return (ENOBUFS);
 2655                 bcopy(buf, opt->ip6po_nexthop, *buf);
 2656                 break;
 2657 
 2658         case IPV6_2292HOPOPTS:
 2659         case IPV6_HOPOPTS:
 2660         {
 2661                 struct ip6_hbh *hbh;
 2662                 int hbhlen;
 2663 
 2664                 /*
 2665                  * XXX: We don't allow a non-privileged user to set ANY HbH
 2666                  * options, since per-option restriction has too much
 2667                  * overhead.
 2668                  */
 2669                 if (cred != NULL) {
 2670                         error = priv_check_cred(cred,
 2671                             PRIV_NETINET_SETHDROPTS, 0);
 2672                         if (error)
 2673                                 return (error);
 2674                 }
 2675 
 2676                 if (len == 0) {
 2677                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
 2678                         break;  /* just remove the option */
 2679                 }
 2680 
 2681                 /* message length validation */
 2682                 if (len < sizeof(struct ip6_hbh))
 2683                         return (EINVAL);
 2684                 hbh = (struct ip6_hbh *)buf;
 2685                 hbhlen = (hbh->ip6h_len + 1) << 3;
 2686                 if (len != hbhlen)
 2687                         return (EINVAL);
 2688 
 2689                 /* turn off the previous option, then set the new option. */
 2690                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
 2691                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
 2692                 if (opt->ip6po_hbh == NULL)
 2693                         return (ENOBUFS);
 2694                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
 2695 
 2696                 break;
 2697         }
 2698 
 2699         case IPV6_2292DSTOPTS:
 2700         case IPV6_DSTOPTS:
 2701         case IPV6_RTHDRDSTOPTS:
 2702         {
 2703                 struct ip6_dest *dest, **newdest = NULL;
 2704                 int destlen;
 2705 
 2706                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
 2707                         error = priv_check_cred(cred,
 2708                             PRIV_NETINET_SETHDROPTS, 0);
 2709                         if (error)
 2710                                 return (error);
 2711                 }
 2712 
 2713                 if (len == 0) {
 2714                         ip6_clearpktopts(opt, optname);
 2715                         break;  /* just remove the option */
 2716                 }
 2717 
 2718                 /* message length validation */
 2719                 if (len < sizeof(struct ip6_dest))
 2720                         return (EINVAL);
 2721                 dest = (struct ip6_dest *)buf;
 2722                 destlen = (dest->ip6d_len + 1) << 3;
 2723                 if (len != destlen)
 2724                         return (EINVAL);
 2725 
 2726                 /*
 2727                  * Determine the position that the destination options header
 2728                  * should be inserted; before or after the routing header.
 2729                  */
 2730                 switch (optname) {
 2731                 case IPV6_2292DSTOPTS:
 2732                         /*
 2733                          * The old advacned API is ambiguous on this point.
 2734                          * Our approach is to determine the position based
 2735                          * according to the existence of a routing header.
 2736                          * Note, however, that this depends on the order of the
 2737                          * extension headers in the ancillary data; the 1st
 2738                          * part of the destination options header must appear
 2739                          * before the routing header in the ancillary data,
 2740                          * too.
 2741                          * RFC3542 solved the ambiguity by introducing
 2742                          * separate ancillary data or option types.
 2743                          */
 2744                         if (opt->ip6po_rthdr == NULL)
 2745                                 newdest = &opt->ip6po_dest1;
 2746                         else
 2747                                 newdest = &opt->ip6po_dest2;
 2748                         break;
 2749                 case IPV6_RTHDRDSTOPTS:
 2750                         newdest = &opt->ip6po_dest1;
 2751                         break;
 2752                 case IPV6_DSTOPTS:
 2753                         newdest = &opt->ip6po_dest2;
 2754                         break;
 2755                 }
 2756 
 2757                 /* turn off the previous option, then set the new option. */
 2758                 ip6_clearpktopts(opt, optname);
 2759                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
 2760                 if (*newdest == NULL)
 2761                         return (ENOBUFS);
 2762                 bcopy(dest, *newdest, destlen);
 2763 
 2764                 break;
 2765         }
 2766 
 2767         case IPV6_2292RTHDR:
 2768         case IPV6_RTHDR:
 2769         {
 2770                 struct ip6_rthdr *rth;
 2771                 int rthlen;
 2772 
 2773                 if (len == 0) {
 2774                         ip6_clearpktopts(opt, IPV6_RTHDR);
 2775                         break;  /* just remove the option */
 2776                 }
 2777 
 2778                 /* message length validation */
 2779                 if (len < sizeof(struct ip6_rthdr))
 2780                         return (EINVAL);
 2781                 rth = (struct ip6_rthdr *)buf;
 2782                 rthlen = (rth->ip6r_len + 1) << 3;
 2783                 if (len != rthlen)
 2784                         return (EINVAL);
 2785 
 2786                 switch (rth->ip6r_type) {
 2787                 case IPV6_RTHDR_TYPE_0:
 2788                         if (rth->ip6r_len == 0) /* must contain one addr */
 2789                                 return (EINVAL);
 2790                         if (rth->ip6r_len % 2) /* length must be even */
 2791                                 return (EINVAL);
 2792                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
 2793                                 return (EINVAL);
 2794                         break;
 2795                 default:
 2796                         return (EINVAL);        /* not supported */
 2797                 }
 2798 
 2799                 /* turn off the previous option */
 2800                 ip6_clearpktopts(opt, IPV6_RTHDR);
 2801                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
 2802                 if (opt->ip6po_rthdr == NULL)
 2803                         return (ENOBUFS);
 2804                 bcopy(rth, opt->ip6po_rthdr, rthlen);
 2805 
 2806                 break;
 2807         }
 2808 
 2809         case IPV6_USE_MIN_MTU:
 2810                 if (len != sizeof(int))
 2811                         return (EINVAL);
 2812                 minmtupolicy = *(int *)buf;
 2813                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
 2814                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
 2815                     minmtupolicy != IP6PO_MINMTU_ALL) {
 2816                         return (EINVAL);
 2817                 }
 2818                 opt->ip6po_minmtu = minmtupolicy;
 2819                 break;
 2820 
 2821         case IPV6_DONTFRAG:
 2822                 if (len != sizeof(int))
 2823                         return (EINVAL);
 2824 
 2825                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
 2826                         /*
 2827                          * we ignore this option for TCP sockets.
 2828                          * (RFC3542 leaves this case unspecified.)
 2829                          */
 2830                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
 2831                 } else
 2832                         opt->ip6po_flags |= IP6PO_DONTFRAG;
 2833                 break;
 2834 
 2835         case IPV6_PREFER_TEMPADDR:
 2836                 if (len != sizeof(int))
 2837                         return (EINVAL);
 2838                 preftemp = *(int *)buf;
 2839                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
 2840                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
 2841                     preftemp != IP6PO_TEMPADDR_PREFER) {
 2842                         return (EINVAL);
 2843                 }
 2844                 opt->ip6po_prefer_tempaddr = preftemp;
 2845                 break;
 2846 
 2847         default:
 2848                 return (ENOPROTOOPT);
 2849         } /* end of switch */
 2850 
 2851         return (0);
 2852 }
 2853 
 2854 /*
 2855  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
 2856  * packet to the input queue of a specified interface.  Note that this
 2857  * calls the output routine of the loopback "driver", but with an interface
 2858  * pointer that might NOT be &loif -- easier than replicating that code here.
 2859  */
 2860 void
 2861 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
 2862 {
 2863         struct mbuf *copym;
 2864         struct ip6_hdr *ip6;
 2865 
 2866         copym = m_copy(m, 0, M_COPYALL);
 2867         if (copym == NULL)
 2868                 return;
 2869 
 2870         /*
 2871          * Make sure to deep-copy IPv6 header portion in case the data
 2872          * is in an mbuf cluster, so that we can safely override the IPv6
 2873          * header portion later.
 2874          */
 2875         if ((copym->m_flags & M_EXT) != 0 ||
 2876             copym->m_len < sizeof(struct ip6_hdr)) {
 2877                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
 2878                 if (copym == NULL)
 2879                         return;
 2880         }
 2881 
 2882 #ifdef DIAGNOSTIC
 2883         if (copym->m_len < sizeof(*ip6)) {
 2884                 m_freem(copym);
 2885                 return;
 2886         }
 2887 #endif
 2888 
 2889         ip6 = mtod(copym, struct ip6_hdr *);
 2890         /*
 2891          * clear embedded scope identifiers if necessary.
 2892          * in6_clearscope will touch the addresses only when necessary.
 2893          */
 2894         in6_clearscope(&ip6->ip6_src);
 2895         in6_clearscope(&ip6->ip6_dst);
 2896 
 2897         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
 2898 }
 2899 
 2900 /*
 2901  * Chop IPv6 header off from the payload.
 2902  */
 2903 static int
 2904 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
 2905 {
 2906         struct mbuf *mh;
 2907         struct ip6_hdr *ip6;
 2908 
 2909         ip6 = mtod(m, struct ip6_hdr *);
 2910         if (m->m_len > sizeof(*ip6)) {
 2911                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
 2912                 if (mh == 0) {
 2913                         m_freem(m);
 2914                         return ENOBUFS;
 2915                 }
 2916                 M_MOVE_PKTHDR(mh, m);
 2917                 MH_ALIGN(mh, sizeof(*ip6));
 2918                 m->m_len -= sizeof(*ip6);
 2919                 m->m_data += sizeof(*ip6);
 2920                 mh->m_next = m;
 2921                 m = mh;
 2922                 m->m_len = sizeof(*ip6);
 2923                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
 2924         }
 2925         exthdrs->ip6e_ip6 = m;
 2926         return 0;
 2927 }
 2928 
 2929 /*
 2930  * Compute IPv6 extension header length.
 2931  */
 2932 int
 2933 ip6_optlen(struct inpcb *in6p)
 2934 {
 2935         int len;
 2936 
 2937         if (!in6p->in6p_outputopts)
 2938                 return 0;
 2939 
 2940         len = 0;
 2941 #define elen(x) \
 2942     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
 2943 
 2944         len += elen(in6p->in6p_outputopts->ip6po_hbh);
 2945         if (in6p->in6p_outputopts->ip6po_rthdr)
 2946                 /* dest1 is valid with rthdr only */
 2947                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
 2948         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
 2949         len += elen(in6p->in6p_outputopts->ip6po_dest2);
 2950         return len;
 2951 #undef elen
 2952 }

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