The Design and Implementation of the FreeBSD Operating System, Second Edition
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sys/netinet6/in6_ifattach.c

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    1 /*      $NetBSD: in6_ifattach.c,v 1.68 2006/11/20 04:16:27 dyoung Exp $ */
    2 /*      $KAME: in6_ifattach.c,v 1.124 2001/07/18 08:32:51 jinmei Exp $  */
    3 
    4 /*
    5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    6  * All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 3. Neither the name of the project nor the names of its contributors
   17  *    may be used to endorse or promote products derived from this software
   18  *    without specific prior written permission.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   30  * SUCH DAMAGE.
   31  */
   32 
   33 #include <sys/cdefs.h>
   34 __KERNEL_RCSID(0, "$NetBSD: in6_ifattach.c,v 1.68 2006/11/20 04:16:27 dyoung Exp $");
   35 
   36 #include <sys/param.h>
   37 #include <sys/systm.h>
   38 #include <sys/malloc.h>
   39 #include <sys/socket.h>
   40 #include <sys/sockio.h>
   41 #include <sys/kernel.h>
   42 #include <sys/syslog.h>
   43 #include <sys/md5.h>
   44 
   45 #include <net/if.h>
   46 #include <net/if_dl.h>
   47 #include <net/if_types.h>
   48 #include <net/route.h>
   49 
   50 #include <netinet/in.h>
   51 #include <netinet/in_var.h>
   52 
   53 #include <netinet/ip6.h>
   54 #include <netinet6/in6_ifattach.h>
   55 #include <netinet6/ip6_var.h>
   56 #include <netinet6/nd6.h>
   57 #include <netinet6/ip6_mroute.h>
   58 #include <netinet6/scope6_var.h>
   59 
   60 #include <net/net_osdep.h>
   61 
   62 unsigned long in6_maxmtu = 0;
   63 
   64 int ip6_auto_linklocal = 1;     /* enable by default */
   65 
   66 struct callout in6_tmpaddrtimer_ch = CALLOUT_INITIALIZER;
   67 
   68 
   69 #if 0
   70 static int get_hostid_ifid __P((struct ifnet *, struct in6_addr *));
   71 #endif
   72 static int get_rand_ifid __P((struct ifnet *, struct in6_addr *));
   73 static int generate_tmp_ifid __P((u_int8_t *, const u_int8_t *, u_int8_t *));
   74 static int get_ifid __P((struct ifnet *, struct ifnet *, struct in6_addr *));
   75 static int in6_ifattach_linklocal __P((struct ifnet *, struct ifnet *));
   76 static int in6_ifattach_loopback __P((struct ifnet *));
   77 
   78 #define EUI64_GBIT      0x01
   79 #define EUI64_UBIT      0x02
   80 #define EUI64_TO_IFID(in6)      do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (/*CONSTCOND*/ 0)
   81 #define EUI64_GROUP(in6)        ((in6)->s6_addr[8] & EUI64_GBIT)
   82 #define EUI64_INDIVIDUAL(in6)   (!EUI64_GROUP(in6))
   83 #define EUI64_LOCAL(in6)        ((in6)->s6_addr[8] & EUI64_UBIT)
   84 #define EUI64_UNIVERSAL(in6)    (!EUI64_LOCAL(in6))
   85 
   86 #define IFID_LOCAL(in6)         (!EUI64_LOCAL(in6))
   87 #define IFID_UNIVERSAL(in6)     (!EUI64_UNIVERSAL(in6))
   88 
   89 #define GEN_TEMPID_RETRY_MAX 5
   90 
   91 #if 0
   92 /*
   93  * Generate a last-resort interface identifier from hostid.
   94  * works only for certain architectures (like sparc).
   95  * also, using hostid itself may constitute a privacy threat, much worse
   96  * than MAC addresses (hostids are used for software licensing).
   97  * maybe we should use MD5(hostid) instead.
   98  */
   99 static int
  100 get_hostid_ifid(ifp, in6)
  101         struct ifnet *ifp;
  102         struct in6_addr *in6;   /* upper 64bits are preserved */
  103 {
  104         int off, len;
  105         static const uint8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
  106         static const uint8_t allone[8] =
  107             { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  108 
  109         if (!hostid)
  110                 return -1;
  111 
  112         /* get up to 8 bytes from the hostid field - should we get */
  113         len = (sizeof(hostid) > 8) ? 8 : sizeof(hostid);
  114         off = sizeof(*in6) - len;
  115         memcpy(&in6->s6_addr[off], &hostid, len);
  116 
  117         /* make sure we do not return anything bogus */
  118         if (memcmp(&in6->s6_addr[8], allzero, sizeof(allzero)))
  119                 return -1;
  120         if (memcmp(&in6->s6_addr[8], allone, sizeof(allone)))
  121                 return -1;
  122 
  123         /* make sure to set "u" bit to local, and "g" bit to individual. */
  124         in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
  125         in6->s6_addr[8] |= EUI64_UBIT;  /* u bit to "local" */
  126 
  127         /* convert EUI64 into IPv6 interface identifier */
  128         EUI64_TO_IFID(in6);
  129 
  130         return 0;
  131 }
  132 #endif
  133 
  134 /*
  135  * Generate a last-resort interface identifier, when the machine has no
  136  * IEEE802/EUI64 address sources.
  137  * The goal here is to get an interface identifier that is
  138  * (1) random enough and (2) does not change across reboot.
  139  * We currently use MD5(hostname) for it.
  140  */
  141 static int
  142 get_rand_ifid(struct ifnet *ifp,
  143         struct in6_addr *in6)   /* upper 64bits are preserved */
  144 {
  145         MD5_CTX ctxt;
  146         u_int8_t digest[16];
  147 
  148 #if 0
  149         /* we need at least several letters as seed for ifid */
  150         if (hostnamelen < 3)
  151                 return -1;
  152 #endif
  153 
  154         /* generate 8 bytes of pseudo-random value. */
  155         memset(&ctxt, 0, sizeof(ctxt));
  156         MD5Init(&ctxt);
  157         MD5Update(&ctxt, (u_char *)hostname, hostnamelen);
  158         MD5Final(digest, &ctxt);
  159 
  160         /* assumes sizeof(digest) > sizeof(ifid) */
  161         memcpy(&in6->s6_addr[8], digest, 8);
  162 
  163         /* make sure to set "u" bit to local, and "g" bit to individual. */
  164         in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
  165         in6->s6_addr[8] |= EUI64_UBIT;  /* u bit to "local" */
  166 
  167         /* convert EUI64 into IPv6 interface identifier */
  168         EUI64_TO_IFID(in6);
  169 
  170         return 0;
  171 }
  172 
  173 static int
  174 generate_tmp_ifid(seed0, seed1, ret)
  175         u_int8_t *seed0, *ret;
  176         const u_int8_t *seed1;
  177 {
  178         MD5_CTX ctxt;
  179         u_int8_t seed[16], digest[16], nullbuf[8];
  180         u_int32_t val32;
  181         /*
  182          * interface ID for subnet anycast addresses.
  183          * XXX: we assume the unicast address range that requires IDs
  184          * in EUI-64 format.
  185          */
  186         static const uint8_t anycast_id[8] = { 0xfd, 0xff, 0xff, 0xff,
  187             0xff, 0xff, 0xff, 0x80 };
  188         static const uint8_t isatap_id[4] = { 0x00, 0x00, 0x5e, 0xfe };
  189         int badid, retry = 0;
  190 
  191         /* If there's no hisotry, start with a random seed. */
  192         memset(nullbuf, 0, sizeof(nullbuf));
  193         if (memcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
  194                 int i;
  195 
  196                 for (i = 0; i < 2; i++) {
  197                         val32 = arc4random();
  198                         memcpy(seed + sizeof(val32) * i, &val32, sizeof(val32));
  199                 }
  200         } else
  201                 memcpy(seed, seed0, 8);
  202 
  203         /* copy the right-most 64-bits of the given address */
  204         /* XXX assumption on the size of IFID */
  205         memcpy(&seed[8], seed1, 8);
  206 
  207   again:
  208         /* for debugging purposes only */
  209 #if 0
  210         {
  211                 int i;
  212 
  213                 printf("generate_tmp_ifid: new randomized ID from: ");
  214                 for (i = 0; i < 16; i++)
  215                         printf("%02x", seed[i]);
  216                 printf(" ");
  217         }
  218 #endif
  219 
  220         /* generate 16 bytes of pseudo-random value. */
  221         memset(&ctxt, 0, sizeof(ctxt));
  222         MD5Init(&ctxt);
  223         MD5Update(&ctxt, seed, sizeof(seed));
  224         MD5Final(digest, &ctxt);
  225 
  226         /*
  227          * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (3)
  228          * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
  229          * left-most bit is numbered 0) to zero.
  230          */
  231         memcpy(ret, digest, 8);
  232         ret[0] &= ~EUI64_UBIT;
  233 
  234         /*
  235          * Reject inappropriate identifiers according to
  236          * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (4)
  237          * At this moment, we reject following cases:
  238          * - all 0 identifier
  239          * - identifiers that conflict with reserved subnet anycast addresses,
  240          *   which are defined in RFC 2526.
  241          * - identifiers that conflict with ISATAP addresses
  242          * - identifiers used in our own addresses
  243          */
  244         badid = 0;
  245         if (memcmp(nullbuf, ret, sizeof(nullbuf)) == 0)
  246                 badid = 1;
  247         else if (memcmp(anycast_id, ret, 7) == 0 &&
  248             (anycast_id[7] & ret[7]) == anycast_id[7]) {
  249                 badid = 1;
  250         } else if (memcmp(isatap_id, ret, sizeof(isatap_id)) == 0)
  251                 badid = 1;
  252         else {
  253                 struct in6_ifaddr *ia;
  254 
  255                 for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
  256                         if (!memcmp(&ia->ia_addr.sin6_addr.s6_addr[8], 
  257                             ret, 8)) {
  258                                 badid = 1;
  259                                 break;
  260                         }
  261                 }
  262         }
  263 
  264         /*
  265          * In the event that an unacceptable identifier has been generated,
  266          * restart the process, using the right-most 64 bits of the MD5 digest
  267          * obtained in place of the history value.
  268          */
  269         if (badid) {
  270                 /* for debugging purposes only */
  271 #if 0
  272                 {
  273                         int i;
  274 
  275                         printf("unacceptable random ID: ");
  276                         for (i = 0; i < 16; i++)
  277                                 printf("%02x", digest[i]);
  278                         printf("\n");
  279                 }
  280 #endif
  281 
  282                 if (++retry < GEN_TEMPID_RETRY_MAX) {
  283                         memcpy(seed, &digest[8], 8);
  284                         goto again;
  285                 } else {
  286                         /*
  287                          * We're so unlucky.  Give up for now, and return
  288                          * all 0 IDs to tell the caller not to make a
  289                          * temporary address.
  290                          */
  291                         nd6log((LOG_NOTICE,
  292                             "generate_tmp_ifid: never found a good ID\n"));
  293                         memset(ret, 0, 8);
  294                 }
  295         }
  296 
  297         /*
  298          * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (6)
  299          * Take the rightmost 64-bits of the MD5 digest and save them in
  300          * stable storage as the history value to be used in the next
  301          * iteration of the algorithm.
  302          */
  303         memcpy(seed0, &digest[8], 8);
  304 
  305         /* for debugging purposes only */
  306 #if 0
  307         {
  308                 int i;
  309 
  310                 printf("to: ");
  311                 for (i = 0; i < 16; i++)
  312                         printf("%02x", digest[i]);
  313                 printf("\n");
  314         }
  315 #endif
  316 
  317         return 0;
  318 }
  319 /*
  320  * Get interface identifier for the specified interface.
  321  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
  322  */
  323 int
  324 in6_get_hw_ifid(ifp, in6)
  325         struct ifnet *ifp;
  326         struct in6_addr *in6;   /* upper 64bits are preserved */
  327 {
  328         struct ifaddr *ifa;
  329         struct sockaddr_dl *sdl;
  330         char *addr;
  331         size_t addrlen;
  332         static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
  333         static u_int8_t allone[8] =
  334                 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  335 
  336         TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
  337                 if (ifa->ifa_addr->sa_family != AF_LINK)
  338                         continue;
  339                 sdl = (struct sockaddr_dl *)ifa->ifa_addr;
  340                 if (sdl == NULL)
  341                         continue;
  342                 if (sdl->sdl_alen == 0)
  343                         continue;
  344 
  345                 goto found;
  346         }
  347 
  348         return -1;
  349 
  350 found:
  351         addr = LLADDR(sdl);
  352         addrlen = sdl->sdl_alen;
  353 
  354         switch (ifp->if_type) {
  355         case IFT_IEEE1394:
  356         case IFT_IEEE80211:
  357                 /* IEEE1394 uses 16byte length address starting with EUI64 */
  358                 if (addrlen > 8)
  359                         addrlen = 8;
  360                 break;
  361         default:
  362                 break;
  363         }
  364 
  365         /* get EUI64 */
  366         switch (ifp->if_type) {
  367         /* IEEE802/EUI64 cases - what others? */
  368         case IFT_ETHER:
  369         case IFT_FDDI:
  370         case IFT_ATM:
  371         case IFT_IEEE1394:
  372         case IFT_IEEE80211:
  373                 /* look at IEEE802/EUI64 only */
  374                 if (addrlen != 8 && addrlen != 6)
  375                         return -1;
  376 
  377                 /*
  378                  * check for invalid MAC address - on bsdi, we see it a lot
  379                  * since wildboar configures all-zero MAC on pccard before
  380                  * card insertion.
  381                  */
  382                 if (memcmp(addr, allzero, addrlen) == 0)
  383                         return -1;
  384                 if (memcmp(addr, allone, addrlen) == 0)
  385                         return -1;
  386 
  387                 /* make EUI64 address */
  388                 if (addrlen == 8)
  389                         memcpy(&in6->s6_addr[8], addr, 8);
  390                 else if (addrlen == 6) {
  391                         in6->s6_addr[8] = addr[0];
  392                         in6->s6_addr[9] = addr[1];
  393                         in6->s6_addr[10] = addr[2];
  394                         in6->s6_addr[11] = 0xff;
  395                         in6->s6_addr[12] = 0xfe;
  396                         in6->s6_addr[13] = addr[3];
  397                         in6->s6_addr[14] = addr[4];
  398                         in6->s6_addr[15] = addr[5];
  399                 }
  400                 break;
  401 
  402         case IFT_ARCNET:
  403                 if (addrlen != 1)
  404                         return -1;
  405                 if (!addr[0])
  406                         return -1;
  407 
  408                 memset(&in6->s6_addr[8], 0, 8);
  409                 in6->s6_addr[15] = addr[0];
  410 
  411                 /*
  412                  * due to insufficient bitwidth, we mark it local.
  413                  */
  414                 in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
  415                 in6->s6_addr[8] |= EUI64_UBIT;  /* u bit to "local" */
  416                 break;
  417 
  418         case IFT_GIF:
  419 #ifdef IFT_STF
  420         case IFT_STF:
  421 #endif
  422                 /*
  423                  * RFC2893 says: "SHOULD use IPv4 address as ifid source".
  424                  * however, IPv4 address is not very suitable as unique
  425                  * identifier source (can be renumbered).
  426                  * we don't do this.
  427                  */
  428                 return -1;
  429 
  430         default:
  431                 return -1;
  432         }
  433 
  434         /* sanity check: g bit must not indicate "group" */
  435         if (EUI64_GROUP(in6))
  436                 return -1;
  437 
  438         /* convert EUI64 into IPv6 interface identifier */
  439         EUI64_TO_IFID(in6);
  440 
  441         /*
  442          * sanity check: ifid must not be all zero, avoid conflict with
  443          * subnet router anycast
  444          */
  445         if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
  446             memcmp(&in6->s6_addr[9], allzero, 7) == 0) {
  447                 return -1;
  448         }
  449 
  450         return 0;
  451 }
  452 
  453 /*
  454  * Get interface identifier for the specified interface.  If it is not
  455  * available on ifp0, borrow interface identifier from other information
  456  * sources.
  457  */
  458 static int
  459 get_ifid(ifp0, altifp, in6)
  460         struct ifnet *ifp0;
  461         struct ifnet *altifp;   /*secondary EUI64 source*/
  462         struct in6_addr *in6;
  463 {
  464         struct ifnet *ifp;
  465 
  466         /* first, try to get it from the interface itself */
  467         if (in6_get_hw_ifid(ifp0, in6) == 0) {
  468                 nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
  469                     if_name(ifp0)));
  470                 goto success;
  471         }
  472 
  473         /* try secondary EUI64 source. this basically is for ATM PVC */
  474         if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
  475                 nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
  476                     if_name(ifp0), if_name(altifp)));
  477                 goto success;
  478         }
  479 
  480         /* next, try to get it from some other hardware interface */
  481         TAILQ_FOREACH(ifp, &ifnet, if_list) {
  482                 if (ifp == ifp0)
  483                         continue;
  484                 if (in6_get_hw_ifid(ifp, in6) != 0)
  485                         continue;
  486 
  487                 /*
  488                  * to borrow ifid from other interface, ifid needs to be
  489                  * globally unique
  490                  */
  491                 if (IFID_UNIVERSAL(in6)) {
  492                         nd6log((LOG_DEBUG,
  493                             "%s: borrow interface identifier from %s\n",
  494                             if_name(ifp0), if_name(ifp)));
  495                         goto success;
  496                 }
  497         }
  498 
  499 #if 0
  500         /* get from hostid - only for certain architectures */
  501         if (get_hostid_ifid(ifp, in6) == 0) {
  502                 nd6log((LOG_DEBUG,
  503                     "%s: interface identifier generated by hostid\n",
  504                     if_name(ifp0)));
  505                 goto success;
  506         }
  507 #endif
  508 
  509         /* last resort: get from random number source */
  510         if (get_rand_ifid(ifp, in6) == 0) {
  511                 nd6log((LOG_DEBUG,
  512                     "%s: interface identifier generated by random number\n",
  513                     if_name(ifp0)));
  514                 goto success;
  515         }
  516 
  517         printf("%s: failed to get interface identifier\n", if_name(ifp0));
  518         return -1;
  519 
  520 success:
  521         nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
  522             if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
  523             in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
  524             in6->s6_addr[14], in6->s6_addr[15]));
  525         return 0;
  526 }
  527 
  528 static int
  529 in6_ifattach_linklocal(ifp, altifp)
  530         struct ifnet *ifp;
  531         struct ifnet *altifp;   /*secondary EUI64 source*/
  532 {
  533         struct in6_ifaddr *ia;
  534         struct in6_aliasreq ifra;
  535         struct nd_prefixctl pr0;
  536         int i, error;
  537 
  538         /*
  539          * configure link-local address.
  540          */
  541         memset(&ifra, 0, sizeof(ifra));
  542 
  543         /*
  544          * in6_update_ifa() does not use ifra_name, but we accurately set it
  545          * for safety.
  546          */
  547         strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
  548 
  549         ifra.ifra_addr.sin6_family = AF_INET6;
  550         ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
  551         ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
  552         ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
  553         if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
  554                 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
  555                 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
  556         } else {
  557                 if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
  558                         nd6log((LOG_ERR,
  559                             "%s: no ifid available\n", if_name(ifp)));
  560                         return (-1);
  561                 }
  562         }
  563         if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
  564                 return (-1);
  565 
  566         ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
  567         ifra.ifra_prefixmask.sin6_family = AF_INET6;
  568         ifra.ifra_prefixmask.sin6_addr = in6mask64;
  569         /* link-local addresses should NEVER expire. */
  570         ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
  571         ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
  572 
  573         /*
  574          * Now call in6_update_ifa() to do a bunch of procedures to configure
  575          * a link-local address. We can set NULL to the 3rd argument, because
  576          * we know there's no other link-local address on the interface
  577          * and therefore we are adding one (instead of updating one).
  578          */
  579         if ((error = in6_update_ifa(ifp, &ifra, NULL,
  580             IN6_IFAUPDATE_DADDELAY)) != 0) {
  581                 /*
  582                  * XXX: When the interface does not support IPv6, this call
  583                  * would fail in the SIOCSIFADDR ioctl.  I believe the
  584                  * notification is rather confusing in this case, so just
  585                  * suppress it.  (jinmei@kame.net 20010130)
  586                  */
  587                 if (error != EAFNOSUPPORT)
  588                         nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
  589                             "configure a link-local address on %s "
  590                             "(errno=%d)\n",
  591                             if_name(ifp), error));
  592                 return (-1);
  593         }
  594 
  595         ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
  596 #ifdef DIAGNOSTIC
  597         if (!ia) {
  598                 panic("ia == NULL in in6_ifattach_linklocal");
  599                 /* NOTREACHED */
  600         }
  601 #endif
  602 
  603         /*
  604          * Make the link-local prefix (fe80::/64%link) as on-link.
  605          * Since we'd like to manage prefixes separately from addresses,
  606          * we make an ND6 prefix structure for the link-local prefix,
  607          * and add it to the prefix list as a never-expire prefix.
  608          * XXX: this change might affect some existing code base...
  609          */
  610         memset(&pr0, 0, sizeof(pr0));
  611         pr0.ndpr_ifp = ifp;
  612         /* this should be 64 at this moment. */
  613         pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
  614         pr0.ndpr_prefix = ifra.ifra_addr;
  615         /* apply the mask for safety. (nd6_prelist_add will apply it again) */
  616         for (i = 0; i < 4; i++) {
  617                 pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
  618                     in6mask64.s6_addr32[i];
  619         }
  620         /*
  621          * Initialize parameters.  The link-local prefix must always be
  622          * on-link, and its lifetimes never expire.
  623          */
  624         pr0.ndpr_raf_onlink = 1;
  625         pr0.ndpr_raf_auto = 1;  /* probably meaningless */
  626         pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
  627         pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
  628         /*
  629          * Since there is no other link-local addresses, nd6_prefix_lookup()
  630          * probably returns NULL.  However, we cannot always expect the result.
  631          * For example, if we first remove the (only) existing link-local
  632          * address, and then reconfigure another one, the prefix is still
  633          * valid with referring to the old link-local address.
  634          */
  635         if (nd6_prefix_lookup(&pr0) == NULL) {
  636                 if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
  637                         return (error);
  638         }
  639 
  640         return 0;
  641 }
  642 
  643 static int
  644 in6_ifattach_loopback(ifp)
  645         struct ifnet *ifp;      /* must be IFT_LOOP */
  646 {
  647         struct in6_aliasreq ifra;
  648         int error;
  649 
  650         memset(&ifra, 0, sizeof(ifra));
  651 
  652         /*
  653          * in6_update_ifa() does not use ifra_name, but we accurately set it
  654          * for safety.
  655          */
  656         strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
  657 
  658         ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
  659         ifra.ifra_prefixmask.sin6_family = AF_INET6;
  660         ifra.ifra_prefixmask.sin6_addr = in6mask128;
  661 
  662         /*
  663          * Always initialize ia_dstaddr (= broadcast address) to loopback
  664          * address.  Follows IPv4 practice - see in_ifinit().
  665          */
  666         ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
  667         ifra.ifra_dstaddr.sin6_family = AF_INET6;
  668         ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
  669 
  670         ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
  671         ifra.ifra_addr.sin6_family = AF_INET6;
  672         ifra.ifra_addr.sin6_addr = in6addr_loopback;
  673 
  674         /* the loopback  address should NEVER expire. */
  675         ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
  676         ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
  677 
  678         /* we don't need to perform DAD on loopback interfaces. */
  679         ifra.ifra_flags |= IN6_IFF_NODAD;
  680 
  681         /*
  682          * We are sure that this is a newly assigned address, so we can set
  683          * NULL to the 3rd arg.
  684          */
  685         if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
  686                 nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
  687                     "the loopback address on %s (errno=%d)\n",
  688                     if_name(ifp), error));
  689                 return (-1);
  690         }
  691 
  692         return 0;
  693 }
  694 
  695 /*
  696  * compute NI group address, based on the current hostname setting.
  697  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
  698  *
  699  * when ifp == NULL, the caller is responsible for filling scopeid.
  700  */
  701 int
  702 in6_nigroup(ifp, name, namelen, sa6)
  703         struct ifnet *ifp;
  704         const char *name;
  705         int namelen;
  706         struct sockaddr_in6 *sa6;
  707 {
  708         const char *p;
  709         u_int8_t *q;
  710         MD5_CTX ctxt;
  711         u_int8_t digest[16];
  712         u_int8_t l;
  713         u_int8_t n[64]; /* a single label must not exceed 63 chars */
  714 
  715         if (!namelen || !name)
  716                 return -1;
  717 
  718         p = name;
  719         while (p && *p && *p != '.' && p - name < namelen)
  720                 p++;
  721         if (p - name > sizeof(n) - 1)
  722                 return -1;      /* label too long */
  723         l = p - name;
  724         strncpy((char *)n, name, l);
  725         n[(int)l] = '\0';
  726         for (q = n; *q; q++) {
  727                 if ('A' <= *q && *q <= 'Z')
  728                         *q = *q - 'A' + 'a';
  729         }
  730 
  731         /* generate 8 bytes of pseudo-random value. */
  732         memset(&ctxt, 0, sizeof(ctxt));
  733         MD5Init(&ctxt);
  734         MD5Update(&ctxt, &l, sizeof(l));
  735         MD5Update(&ctxt, n, l);
  736         MD5Final(digest, &ctxt);
  737 
  738         memset(sa6, 0, sizeof(*sa6));
  739         sa6->sin6_family = AF_INET6;
  740         sa6->sin6_len = sizeof(*sa6);
  741         sa6->sin6_addr.s6_addr16[0] = htons(0xff02);
  742         sa6->sin6_addr.s6_addr8[11] = 2;
  743         memcpy(&sa6->sin6_addr.s6_addr32[3], digest,
  744             sizeof(sa6->sin6_addr.s6_addr32[3]));
  745         if (in6_setscope(&sa6->sin6_addr, ifp, NULL))
  746                 return (-1); /* XXX: should not fail */
  747 
  748         return 0;
  749 }
  750 
  751 /*
  752  * XXX multiple loopback interface needs more care.  for instance,
  753  * nodelocal address needs to be configured onto only one of them.
  754  * XXX multiple link-local address case
  755  */
  756 void
  757 in6_ifattach(ifp, altifp)
  758         struct ifnet *ifp;
  759         struct ifnet *altifp;   /* secondary EUI64 source */
  760 {
  761         struct in6_ifaddr *ia;
  762         struct in6_addr in6;
  763 
  764         /* some of the interfaces are inherently not IPv6 capable */
  765         switch (ifp->if_type) {
  766         case IFT_BRIDGE:
  767 #ifdef IFT_PFLOG
  768         case IFT_PFLOG:
  769 #endif
  770 #ifdef IFT_PFSYNC
  771         case IFT_PFSYNC:
  772 #endif
  773                 return;
  774         }
  775 
  776         /*
  777          * if link mtu is too small, don't try to configure IPv6.
  778          * remember there could be some link-layer that has special
  779          * fragmentation logic.
  780          */
  781         if (ifp->if_mtu < IPV6_MMTU) {
  782                 nd6log((LOG_INFO, "in6_ifattach: "
  783                     "%s has too small MTU, IPv6 not enabled\n",
  784                     if_name(ifp)));
  785                 return;
  786         }
  787 
  788         /* create a multicast kludge storage (if we have not had one) */
  789         in6_createmkludge(ifp);
  790 
  791         /*
  792          * quirks based on interface type
  793          */
  794         switch (ifp->if_type) {
  795 #ifdef IFT_STF
  796         case IFT_STF:
  797                 /*
  798                  * 6to4 interface is a very special kind of beast.
  799                  * no multicast, no linklocal.  RFC2529 specifies how to make
  800                  * linklocals for 6to4 interface, but there's no use and
  801                  * it is rather harmful to have one.
  802                  */
  803                 return;
  804 #endif
  805         case IFT_CARP:
  806                 return;
  807         default:
  808                 break;
  809         }
  810 
  811         /*
  812          * usually, we require multicast capability to the interface
  813          */
  814         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
  815                 nd6log((LOG_INFO, "in6_ifattach: "
  816                     "%s is not multicast capable, IPv6 not enabled\n",
  817                     if_name(ifp)));
  818                 return;
  819         }
  820 
  821         /*
  822          * assign loopback address for loopback interface.
  823          * XXX multiple loopback interface case.
  824          */
  825         if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
  826                 in6 = in6addr_loopback;
  827                 if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
  828                         if (in6_ifattach_loopback(ifp) != 0)
  829                                 return;
  830                 }
  831         }
  832 
  833         /*
  834          * assign a link-local address, if there's none.
  835          */
  836         if (ip6_auto_linklocal) {
  837                 ia = in6ifa_ifpforlinklocal(ifp, 0);
  838                 if (ia == NULL) {
  839                         if (in6_ifattach_linklocal(ifp, altifp) == 0) {
  840                                 /* linklocal address assigned */
  841                         } else {
  842                                 /* failed to assign linklocal address. bark? */
  843                         }
  844                 }
  845         }
  846 }
  847 
  848 /*
  849  * NOTE: in6_ifdetach() does not support loopback if at this moment.
  850  * We don't need this function in bsdi, because interfaces are never removed
  851  * from the ifnet list in bsdi.
  852  */
  853 void
  854 in6_ifdetach(ifp)
  855         struct ifnet *ifp;
  856 {
  857         struct in6_ifaddr *ia, *oia;
  858         struct ifaddr *ifa, *next;
  859         struct rtentry *rt;
  860         short rtflags;
  861         struct in6_multi_mship *imm;
  862 
  863         /* remove ip6_mrouter stuff */
  864         ip6_mrouter_detach(ifp);
  865 
  866         /* remove neighbor management table */
  867         nd6_purge(ifp);
  868 
  869         /* nuke any of IPv6 addresses we have */
  870         for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa; ifa = next) {
  871                 next = TAILQ_NEXT(ifa, ifa_list);
  872                 if (ifa->ifa_addr->sa_family != AF_INET6)
  873                         continue;
  874                 in6_purgeaddr(ifa);
  875         }
  876 
  877         /* undo everything done by in6_ifattach(), just in case */
  878         for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa; ifa = next) {
  879                 next = TAILQ_NEXT(ifa, ifa_list);
  880 
  881                 if (ifa->ifa_addr->sa_family != AF_INET6
  882                  || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
  883                         continue;
  884                 }
  885 
  886                 ia = (struct in6_ifaddr *)ifa;
  887 
  888                 /*
  889                  * leave from multicast groups we have joined for the interface
  890                  */
  891                 while ((imm = LIST_FIRST(&ia->ia6_memberships)) != NULL) {
  892                         LIST_REMOVE(imm, i6mm_chain);
  893                         in6_leavegroup(imm);
  894                 }
  895 
  896                 /* remove from the routing table */
  897                 if ((ia->ia_flags & IFA_ROUTE) &&
  898                     (rt = rtalloc1((struct sockaddr *)&ia->ia_addr, 0))) {
  899                         rtflags = rt->rt_flags;
  900                         rtfree(rt);
  901                         rtrequest(RTM_DELETE, (struct sockaddr *)&ia->ia_addr,
  902                             (struct sockaddr *)&ia->ia_addr,
  903                             (struct sockaddr *)&ia->ia_prefixmask,
  904                             rtflags, (struct rtentry **)0);
  905                 }
  906 
  907                 /* remove from the linked list */
  908                 TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
  909                 IFAFREE(&ia->ia_ifa);
  910 
  911                 /* also remove from the IPv6 address chain(itojun&jinmei) */
  912                 oia = ia;
  913                 if (oia == (ia = in6_ifaddr))
  914                         in6_ifaddr = ia->ia_next;
  915                 else {
  916                         while (ia->ia_next && (ia->ia_next != oia))
  917                                 ia = ia->ia_next;
  918                         if (ia->ia_next)
  919                                 ia->ia_next = oia->ia_next;
  920                         else {
  921                                 nd6log((LOG_ERR,
  922                                     "%s: didn't unlink in6ifaddr from list\n",
  923                                     if_name(ifp)));
  924                         }
  925                 }
  926 
  927                 IFAFREE(&oia->ia_ifa);
  928         }
  929 
  930         /* cleanup multicast address kludge table, if there is any */
  931         in6_purgemkludge(ifp);
  932 
  933         /*
  934          * remove neighbor management table.  we call it twice just to make
  935          * sure we nuke everything.  maybe we need just one call.
  936          * XXX: since the first call did not release addresses, some prefixes
  937          * might remain.  We should call nd6_purge() again to release the
  938          * prefixes after removing all addresses above.
  939          * (Or can we just delay calling nd6_purge until at this point?)
  940          */
  941         nd6_purge(ifp);
  942 }
  943 
  944 int
  945 in6_get_tmpifid(ifp, retbuf, baseid, generate)
  946         struct ifnet *ifp;
  947         u_int8_t *retbuf;
  948         const u_int8_t *baseid;
  949         int generate;
  950 {
  951         u_int8_t nullbuf[8];
  952         struct nd_ifinfo *ndi = ND_IFINFO(ifp);
  953 
  954         memset(nullbuf, 0, sizeof(nullbuf));
  955         if (memcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
  956                 /* we've never created a random ID.  Create a new one. */
  957                 generate = 1;
  958         }
  959 
  960         if (generate) {
  961                 memcpy(ndi->randomseed1, baseid, sizeof(ndi->randomseed1));
  962 
  963                 /* generate_tmp_ifid will update seedn and buf */
  964                 (void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
  965                     ndi->randomid);
  966         }
  967         memcpy(retbuf, ndi->randomid, 8);
  968         if (generate && memcmp(retbuf, nullbuf, sizeof(nullbuf)) == 0) {
  969                 /* generate_tmp_ifid could not found a good ID. */
  970                 return (-1);
  971         }
  972 
  973         return (0);
  974 }
  975 
  976 void
  977 in6_tmpaddrtimer(void *ignored_arg)
  978 {
  979         struct nd_ifinfo *ndi;
  980         u_int8_t nullbuf[8];
  981         struct ifnet *ifp;
  982         int s = splsoftnet();
  983 
  984         callout_reset(&in6_tmpaddrtimer_ch,
  985             (ip6_temp_preferred_lifetime - ip6_desync_factor -
  986             ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, NULL);
  987 
  988         memset(nullbuf, 0, sizeof(nullbuf));
  989         for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
  990                 ndi = ND_IFINFO(ifp);
  991                 if (memcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
  992                         /*
  993                          * We've been generating a random ID on this interface.
  994                          * Create a new one.
  995                          */
  996                         (void)generate_tmp_ifid(ndi->randomseed0,
  997                             ndi->randomseed1, ndi->randomid);
  998                 }
  999         }
 1000 
 1001         splx(s);
 1002 }

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