The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/in6_ifattach.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: in6_ifattach.c,v 1.118 2001/05/24 07:44:00 itojun Exp $
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD$");
   34 
   35 #include <sys/param.h>
   36 #include <sys/systm.h>
   37 #include <sys/malloc.h>
   38 #include <sys/socket.h>
   39 #include <sys/sockio.h>
   40 #include <sys/jail.h>
   41 #include <sys/kernel.h>
   42 #include <sys/proc.h>
   43 #include <sys/syslog.h>
   44 #include <sys/md5.h>
   45 
   46 #include <net/if.h>
   47 #include <net/if_dl.h>
   48 #include <net/if_types.h>
   49 #include <net/route.h>
   50 #include <net/vnet.h>
   51 
   52 #include <netinet/in.h>
   53 #include <netinet/in_var.h>
   54 #include <netinet/if_ether.h>
   55 #include <netinet/in_pcb.h>
   56 #include <netinet/ip_var.h>
   57 #include <netinet/udp.h>
   58 #include <netinet/udp_var.h>
   59 
   60 #include <netinet/ip6.h>
   61 #include <netinet6/ip6_var.h>
   62 #include <netinet6/in6_var.h>
   63 #include <netinet6/in6_pcb.h>
   64 #include <netinet6/in6_ifattach.h>
   65 #include <netinet6/ip6_var.h>
   66 #include <netinet6/nd6.h>
   67 #include <netinet6/mld6_var.h>
   68 #include <netinet6/scope6_var.h>
   69 
   70 VNET_DEFINE(unsigned long, in6_maxmtu) = 0;
   71 
   72 #ifdef IP6_AUTO_LINKLOCAL
   73 VNET_DEFINE(int, ip6_auto_linklocal) = IP6_AUTO_LINKLOCAL;
   74 #else
   75 VNET_DEFINE(int, ip6_auto_linklocal) = 1;       /* enabled by default */
   76 #endif
   77 
   78 VNET_DEFINE(struct callout, in6_tmpaddrtimer_ch);
   79 #define V_in6_tmpaddrtimer_ch           VNET(in6_tmpaddrtimer_ch)
   80 
   81 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
   82 #define V_ripcbinfo                     VNET(ripcbinfo)
   83 
   84 static int get_rand_ifid(struct ifnet *, struct in6_addr *);
   85 static int generate_tmp_ifid(u_int8_t *, const u_int8_t *, u_int8_t *);
   86 static int get_ifid(struct ifnet *, struct ifnet *, struct in6_addr *);
   87 static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *);
   88 static int in6_ifattach_loopback(struct ifnet *);
   89 static void in6_purgemaddrs(struct ifnet *);
   90 
   91 #define EUI64_GBIT      0x01
   92 #define EUI64_UBIT      0x02
   93 #define EUI64_TO_IFID(in6)      do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
   94 #define EUI64_GROUP(in6)        ((in6)->s6_addr[8] & EUI64_GBIT)
   95 #define EUI64_INDIVIDUAL(in6)   (!EUI64_GROUP(in6))
   96 #define EUI64_LOCAL(in6)        ((in6)->s6_addr[8] & EUI64_UBIT)
   97 #define EUI64_UNIVERSAL(in6)    (!EUI64_LOCAL(in6))
   98 
   99 #define IFID_LOCAL(in6)         (!EUI64_LOCAL(in6))
  100 #define IFID_UNIVERSAL(in6)     (!EUI64_UNIVERSAL(in6))
  101 
  102 /*
  103  * Generate a last-resort interface identifier, when the machine has no
  104  * IEEE802/EUI64 address sources.
  105  * The goal here is to get an interface identifier that is
  106  * (1) random enough and (2) does not change across reboot.
  107  * We currently use MD5(hostname) for it.
  108  *
  109  * in6 - upper 64bits are preserved
  110  */
  111 static int
  112 get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
  113 {
  114         MD5_CTX ctxt;
  115         struct prison *pr;
  116         u_int8_t digest[16];
  117         int hostnamelen;
  118 
  119         pr = curthread->td_ucred->cr_prison;
  120         mtx_lock(&pr->pr_mtx);
  121         hostnamelen = strlen(pr->pr_hostname);
  122 #if 0
  123         /* we need at least several letters as seed for ifid */
  124         if (hostnamelen < 3) {
  125                 mtx_unlock(&pr->pr_mtx);
  126                 return -1;
  127         }
  128 #endif
  129 
  130         /* generate 8 bytes of pseudo-random value. */
  131         bzero(&ctxt, sizeof(ctxt));
  132         MD5Init(&ctxt);
  133         MD5Update(&ctxt, pr->pr_hostname, hostnamelen);
  134         mtx_unlock(&pr->pr_mtx);
  135         MD5Final(digest, &ctxt);
  136 
  137         /* assumes sizeof(digest) > sizeof(ifid) */
  138         bcopy(digest, &in6->s6_addr[8], 8);
  139 
  140         /* make sure to set "u" bit to local, and "g" bit to individual. */
  141         in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
  142         in6->s6_addr[8] |= EUI64_UBIT;  /* u bit to "local" */
  143 
  144         /* convert EUI64 into IPv6 interface identifier */
  145         EUI64_TO_IFID(in6);
  146 
  147         return 0;
  148 }
  149 
  150 static int
  151 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
  152 {
  153         MD5_CTX ctxt;
  154         u_int8_t seed[16], digest[16], nullbuf[8];
  155         u_int32_t val32;
  156 
  157         /* If there's no history, start with a random seed. */
  158         bzero(nullbuf, sizeof(nullbuf));
  159         if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
  160                 int i;
  161 
  162                 for (i = 0; i < 2; i++) {
  163                         val32 = arc4random();
  164                         bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
  165                 }
  166         } else
  167                 bcopy(seed0, seed, 8);
  168 
  169         /* copy the right-most 64-bits of the given address */
  170         /* XXX assumption on the size of IFID */
  171         bcopy(seed1, &seed[8], 8);
  172 
  173         if (0) {                /* for debugging purposes only */
  174                 int i;
  175 
  176                 printf("generate_tmp_ifid: new randomized ID from: ");
  177                 for (i = 0; i < 16; i++)
  178                         printf("%02x", seed[i]);
  179                 printf(" ");
  180         }
  181 
  182         /* generate 16 bytes of pseudo-random value. */
  183         bzero(&ctxt, sizeof(ctxt));
  184         MD5Init(&ctxt);
  185         MD5Update(&ctxt, seed, sizeof(seed));
  186         MD5Final(digest, &ctxt);
  187 
  188         /*
  189          * RFC 3041 3.2.1. (3)
  190          * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
  191          * left-most bit is numbered 0) to zero.
  192          */
  193         bcopy(digest, ret, 8);
  194         ret[0] &= ~EUI64_UBIT;
  195 
  196         /*
  197          * XXX: we'd like to ensure that the generated value is not zero
  198          * for simplicity.  If the caclculated digest happens to be zero,
  199          * use a random non-zero value as the last resort.
  200          */
  201         if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
  202                 nd6log((LOG_INFO,
  203                     "generate_tmp_ifid: computed MD5 value is zero.\n"));
  204 
  205                 val32 = arc4random();
  206                 val32 = 1 + (val32 % (0xffffffff - 1));
  207         }
  208 
  209         /*
  210          * RFC 3041 3.2.1. (4)
  211          * Take the rightmost 64-bits of the MD5 digest and save them in
  212          * stable storage as the history value to be used in the next
  213          * iteration of the algorithm.
  214          */
  215         bcopy(&digest[8], seed0, 8);
  216 
  217         if (0) {                /* for debugging purposes only */
  218                 int i;
  219 
  220                 printf("to: ");
  221                 for (i = 0; i < 16; i++)
  222                         printf("%02x", digest[i]);
  223                 printf("\n");
  224         }
  225 
  226         return 0;
  227 }
  228 
  229 /*
  230  * Get interface identifier for the specified interface.
  231  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
  232  *
  233  * in6 - upper 64bits are preserved
  234  */
  235 int
  236 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
  237 {
  238         struct ifaddr *ifa;
  239         struct sockaddr_dl *sdl;
  240         u_int8_t *addr;
  241         size_t addrlen;
  242         static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
  243         static u_int8_t allone[8] =
  244                 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  245 
  246         IF_ADDR_RLOCK(ifp);
  247         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
  248                 if (ifa->ifa_addr->sa_family != AF_LINK)
  249                         continue;
  250                 sdl = (struct sockaddr_dl *)ifa->ifa_addr;
  251                 if (sdl == NULL)
  252                         continue;
  253                 if (sdl->sdl_alen == 0)
  254                         continue;
  255 
  256                 goto found;
  257         }
  258         IF_ADDR_RUNLOCK(ifp);
  259 
  260         return -1;
  261 
  262 found:
  263         IF_ADDR_LOCK_ASSERT(ifp);
  264         addr = LLADDR(sdl);
  265         addrlen = sdl->sdl_alen;
  266 
  267         /* get EUI64 */
  268         switch (ifp->if_type) {
  269         case IFT_ETHER:
  270         case IFT_L2VLAN:
  271         case IFT_FDDI:
  272         case IFT_ISO88025:
  273         case IFT_ATM:
  274         case IFT_IEEE1394:
  275 #ifdef IFT_IEEE80211
  276         case IFT_IEEE80211:
  277 #endif
  278                 /* IEEE802/EUI64 cases - what others? */
  279                 /* IEEE1394 uses 16byte length address starting with EUI64 */
  280                 if (addrlen > 8)
  281                         addrlen = 8;
  282 
  283                 /* look at IEEE802/EUI64 only */
  284                 if (addrlen != 8 && addrlen != 6) {
  285                         IF_ADDR_RUNLOCK(ifp);
  286                         return -1;
  287                 }
  288 
  289                 /*
  290                  * check for invalid MAC address - on bsdi, we see it a lot
  291                  * since wildboar configures all-zero MAC on pccard before
  292                  * card insertion.
  293                  */
  294                 if (bcmp(addr, allzero, addrlen) == 0) {
  295                         IF_ADDR_RUNLOCK(ifp);
  296                         return -1;
  297                 }
  298                 if (bcmp(addr, allone, addrlen) == 0) {
  299                         IF_ADDR_RUNLOCK(ifp);
  300                         return -1;
  301                 }
  302 
  303                 /* make EUI64 address */
  304                 if (addrlen == 8)
  305                         bcopy(addr, &in6->s6_addr[8], 8);
  306                 else if (addrlen == 6) {
  307                         in6->s6_addr[8] = addr[0];
  308                         in6->s6_addr[9] = addr[1];
  309                         in6->s6_addr[10] = addr[2];
  310                         in6->s6_addr[11] = 0xff;
  311                         in6->s6_addr[12] = 0xfe;
  312                         in6->s6_addr[13] = addr[3];
  313                         in6->s6_addr[14] = addr[4];
  314                         in6->s6_addr[15] = addr[5];
  315                 }
  316                 break;
  317 
  318         case IFT_ARCNET:
  319                 if (addrlen != 1) {
  320                         IF_ADDR_RUNLOCK(ifp);
  321                         return -1;
  322                 }
  323                 if (!addr[0]) {
  324                         IF_ADDR_RUNLOCK(ifp);
  325                         return -1;
  326                 }
  327 
  328                 bzero(&in6->s6_addr[8], 8);
  329                 in6->s6_addr[15] = addr[0];
  330 
  331                 /*
  332                  * due to insufficient bitwidth, we mark it local.
  333                  */
  334                 in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
  335                 in6->s6_addr[8] |= EUI64_UBIT;  /* u bit to "local" */
  336                 break;
  337 
  338         case IFT_GIF:
  339 #ifdef IFT_STF
  340         case IFT_STF:
  341 #endif
  342                 /*
  343                  * RFC2893 says: "SHOULD use IPv4 address as ifid source".
  344                  * however, IPv4 address is not very suitable as unique
  345                  * identifier source (can be renumbered).
  346                  * we don't do this.
  347                  */
  348                 IF_ADDR_RUNLOCK(ifp);
  349                 return -1;
  350 
  351         default:
  352                 IF_ADDR_RUNLOCK(ifp);
  353                 return -1;
  354         }
  355 
  356         /* sanity check: g bit must not indicate "group" */
  357         if (EUI64_GROUP(in6)) {
  358                 IF_ADDR_RUNLOCK(ifp);
  359                 return -1;
  360         }
  361 
  362         /* convert EUI64 into IPv6 interface identifier */
  363         EUI64_TO_IFID(in6);
  364 
  365         /*
  366          * sanity check: ifid must not be all zero, avoid conflict with
  367          * subnet router anycast
  368          */
  369         if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
  370             bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
  371                 IF_ADDR_RUNLOCK(ifp);
  372                 return -1;
  373         }
  374 
  375         IF_ADDR_RUNLOCK(ifp);
  376         return 0;
  377 }
  378 
  379 /*
  380  * Get interface identifier for the specified interface.  If it is not
  381  * available on ifp0, borrow interface identifier from other information
  382  * sources.
  383  *
  384  * altifp - secondary EUI64 source
  385  */
  386 static int
  387 get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
  388     struct in6_addr *in6)
  389 {
  390         struct ifnet *ifp;
  391 
  392         /* first, try to get it from the interface itself */
  393         if (in6_get_hw_ifid(ifp0, in6) == 0) {
  394                 nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
  395                     if_name(ifp0)));
  396                 goto success;
  397         }
  398 
  399         /* try secondary EUI64 source. this basically is for ATM PVC */
  400         if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
  401                 nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
  402                     if_name(ifp0), if_name(altifp)));
  403                 goto success;
  404         }
  405 
  406         /* next, try to get it from some other hardware interface */
  407         IFNET_RLOCK_NOSLEEP();
  408         TAILQ_FOREACH(ifp, &V_ifnet, if_list) {
  409                 if (ifp == ifp0)
  410                         continue;
  411                 if (in6_get_hw_ifid(ifp, in6) != 0)
  412                         continue;
  413 
  414                 /*
  415                  * to borrow ifid from other interface, ifid needs to be
  416                  * globally unique
  417                  */
  418                 if (IFID_UNIVERSAL(in6)) {
  419                         nd6log((LOG_DEBUG,
  420                             "%s: borrow interface identifier from %s\n",
  421                             if_name(ifp0), if_name(ifp)));
  422                         IFNET_RUNLOCK_NOSLEEP();
  423                         goto success;
  424                 }
  425         }
  426         IFNET_RUNLOCK_NOSLEEP();
  427 
  428         /* last resort: get from random number source */
  429         if (get_rand_ifid(ifp, in6) == 0) {
  430                 nd6log((LOG_DEBUG,
  431                     "%s: interface identifier generated by random number\n",
  432                     if_name(ifp0)));
  433                 goto success;
  434         }
  435 
  436         printf("%s: failed to get interface identifier\n", if_name(ifp0));
  437         return -1;
  438 
  439 success:
  440         nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
  441             if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
  442             in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
  443             in6->s6_addr[14], in6->s6_addr[15]));
  444         return 0;
  445 }
  446 
  447 /*
  448  * altifp - secondary EUI64 source
  449  */
  450 static int
  451 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
  452 {
  453         struct in6_ifaddr *ia;
  454         struct in6_aliasreq ifra;
  455         struct nd_prefixctl pr0;
  456         int i, error;
  457 
  458         /*
  459          * configure link-local address.
  460          */
  461         bzero(&ifra, sizeof(ifra));
  462 
  463         /*
  464          * in6_update_ifa() does not use ifra_name, but we accurately set it
  465          * for safety.
  466          */
  467         strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
  468 
  469         ifra.ifra_addr.sin6_family = AF_INET6;
  470         ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
  471         ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
  472         ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
  473         if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
  474                 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
  475                 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
  476         } else {
  477                 if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
  478                         nd6log((LOG_ERR,
  479                             "%s: no ifid available\n", if_name(ifp)));
  480                         return (-1);
  481                 }
  482         }
  483         if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
  484                 return (-1);
  485 
  486         ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
  487         ifra.ifra_prefixmask.sin6_family = AF_INET6;
  488         ifra.ifra_prefixmask.sin6_addr = in6mask64;
  489         /* link-local addresses should NEVER expire. */
  490         ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
  491         ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
  492 
  493         /*
  494          * Now call in6_update_ifa() to do a bunch of procedures to configure
  495          * a link-local address. We can set the 3rd argument to NULL, because
  496          * we know there's no other link-local address on the interface
  497          * and therefore we are adding one (instead of updating one).
  498          */
  499         if ((error = in6_update_ifa(ifp, &ifra, NULL,
  500                                     IN6_IFAUPDATE_DADDELAY)) != 0) {
  501                 /*
  502                  * XXX: When the interface does not support IPv6, this call
  503                  * would fail in the SIOCSIFADDR ioctl.  I believe the
  504                  * notification is rather confusing in this case, so just
  505                  * suppress it.  (jinmei@kame.net 20010130)
  506                  */
  507                 if (error != EAFNOSUPPORT)
  508                         nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
  509                             "configure a link-local address on %s "
  510                             "(errno=%d)\n",
  511                             if_name(ifp), error));
  512                 return (-1);
  513         }
  514 
  515         ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
  516         KASSERT(ia != NULL, ("%s: ia == NULL, ifp=%p", __func__, ifp));
  517 
  518         ifa_free(&ia->ia_ifa);
  519 
  520         /*
  521          * Make the link-local prefix (fe80::%link/64) as on-link.
  522          * Since we'd like to manage prefixes separately from addresses,
  523          * we make an ND6 prefix structure for the link-local prefix,
  524          * and add it to the prefix list as a never-expire prefix.
  525          * XXX: this change might affect some existing code base...
  526          */
  527         bzero(&pr0, sizeof(pr0));
  528         pr0.ndpr_ifp = ifp;
  529         /* this should be 64 at this moment. */
  530         pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
  531         pr0.ndpr_prefix = ifra.ifra_addr;
  532         /* apply the mask for safety. (nd6_prelist_add will apply it again) */
  533         for (i = 0; i < 4; i++) {
  534                 pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
  535                     in6mask64.s6_addr32[i];
  536         }
  537         /*
  538          * Initialize parameters.  The link-local prefix must always be
  539          * on-link, and its lifetimes never expire.
  540          */
  541         pr0.ndpr_raf_onlink = 1;
  542         pr0.ndpr_raf_auto = 1;  /* probably meaningless */
  543         pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
  544         pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
  545         /*
  546          * Since there is no other link-local addresses, nd6_prefix_lookup()
  547          * probably returns NULL.  However, we cannot always expect the result.
  548          * For example, if we first remove the (only) existing link-local
  549          * address, and then reconfigure another one, the prefix is still
  550          * valid with referring to the old link-local address.
  551          */
  552         if (nd6_prefix_lookup(&pr0) == NULL) {
  553                 if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
  554                         return (error);
  555         }
  556 
  557         return 0;
  558 }
  559 
  560 /*
  561  * ifp - must be IFT_LOOP
  562  */
  563 static int
  564 in6_ifattach_loopback(struct ifnet *ifp)
  565 {
  566         struct in6_aliasreq ifra;
  567         int error;
  568 
  569         bzero(&ifra, sizeof(ifra));
  570 
  571         /*
  572          * in6_update_ifa() does not use ifra_name, but we accurately set it
  573          * for safety.
  574          */
  575         strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
  576 
  577         ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
  578         ifra.ifra_prefixmask.sin6_family = AF_INET6;
  579         ifra.ifra_prefixmask.sin6_addr = in6mask128;
  580 
  581         /*
  582          * Always initialize ia_dstaddr (= broadcast address) to loopback
  583          * address.  Follows IPv4 practice - see in_ifinit().
  584          */
  585         ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
  586         ifra.ifra_dstaddr.sin6_family = AF_INET6;
  587         ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
  588 
  589         ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
  590         ifra.ifra_addr.sin6_family = AF_INET6;
  591         ifra.ifra_addr.sin6_addr = in6addr_loopback;
  592 
  593         /* the loopback  address should NEVER expire. */
  594         ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
  595         ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
  596 
  597         /* we don't need to perform DAD on loopback interfaces. */
  598         ifra.ifra_flags |= IN6_IFF_NODAD;
  599 
  600         /* skip registration to the prefix list. XXX should be temporary. */
  601         ifra.ifra_flags |= IN6_IFF_NOPFX;
  602 
  603         /*
  604          * We are sure that this is a newly assigned address, so we can set
  605          * NULL to the 3rd arg.
  606          */
  607         if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
  608                 nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
  609                     "the loopback address on %s (errno=%d)\n",
  610                     if_name(ifp), error));
  611                 return (-1);
  612         }
  613 
  614         return 0;
  615 }
  616 
  617 /*
  618  * compute NI group address, based on the current hostname setting.
  619  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
  620  *
  621  * when ifp == NULL, the caller is responsible for filling scopeid.
  622  */
  623 int
  624 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
  625     struct in6_addr *in6)
  626 {
  627         struct prison *pr;
  628         const char *p;
  629         u_char *q;
  630         MD5_CTX ctxt;
  631         u_int8_t digest[16];
  632         char l;
  633         char n[64];     /* a single label must not exceed 63 chars */
  634 
  635         /*
  636          * If no name is given and namelen is -1,
  637          * we try to do the hostname lookup ourselves.
  638          */
  639         if (!name && namelen == -1) {
  640                 pr = curthread->td_ucred->cr_prison;
  641                 mtx_lock(&pr->pr_mtx);
  642                 name = pr->pr_hostname;
  643                 namelen = strlen(name);
  644         } else
  645                 pr = NULL;
  646         if (!name || !namelen) {
  647                 if (pr != NULL)
  648                         mtx_unlock(&pr->pr_mtx);
  649                 return -1;
  650         }
  651 
  652         p = name;
  653         while (p && *p && *p != '.' && p - name < namelen)
  654                 p++;
  655         if (p == name || p - name > sizeof(n) - 1) {
  656                 if (pr != NULL)
  657                         mtx_unlock(&pr->pr_mtx);
  658                 return -1;      /* label too long */
  659         }
  660         l = p - name;
  661         strncpy(n, name, l);
  662         if (pr != NULL)
  663                 mtx_unlock(&pr->pr_mtx);
  664         n[(int)l] = '\0';
  665         for (q = n; *q; q++) {
  666                 if ('A' <= *q && *q <= 'Z')
  667                         *q = *q - 'A' + 'a';
  668         }
  669 
  670         /* generate 8 bytes of pseudo-random value. */
  671         bzero(&ctxt, sizeof(ctxt));
  672         MD5Init(&ctxt);
  673         MD5Update(&ctxt, &l, sizeof(l));
  674         MD5Update(&ctxt, n, l);
  675         MD5Final(digest, &ctxt);
  676 
  677         bzero(in6, sizeof(*in6));
  678         in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  679         in6->s6_addr8[11] = 2;
  680         bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
  681         if (in6_setscope(in6, ifp, NULL))
  682                 return (-1); /* XXX: should not fail */
  683 
  684         return 0;
  685 }
  686 
  687 /*
  688  * XXX multiple loopback interface needs more care.  for instance,
  689  * nodelocal address needs to be configured onto only one of them.
  690  * XXX multiple link-local address case
  691  *
  692  * altifp - secondary EUI64 source
  693  */
  694 void
  695 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
  696 {
  697         struct in6_ifaddr *ia;
  698         struct in6_addr in6;
  699 
  700         /* some of the interfaces are inherently not IPv6 capable */
  701         switch (ifp->if_type) {
  702         case IFT_PFLOG:
  703         case IFT_PFSYNC:
  704         case IFT_CARP:
  705                 return;
  706         }
  707 
  708         /*
  709          * quirks based on interface type
  710          */
  711         switch (ifp->if_type) {
  712 #ifdef IFT_STF
  713         case IFT_STF:
  714                 /*
  715                  * 6to4 interface is a very special kind of beast.
  716                  * no multicast, no linklocal.  RFC2529 specifies how to make
  717                  * linklocals for 6to4 interface, but there's no use and
  718                  * it is rather harmful to have one.
  719                  */
  720                 goto statinit;
  721 #endif
  722         default:
  723                 break;
  724         }
  725 
  726         /*
  727          * usually, we require multicast capability to the interface
  728          */
  729         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
  730                 nd6log((LOG_INFO, "in6_ifattach: "
  731                     "%s is not multicast capable, IPv6 not enabled\n",
  732                     if_name(ifp)));
  733                 return;
  734         }
  735 
  736         /*
  737          * assign loopback address for loopback interface.
  738          * XXX multiple loopback interface case.
  739          */
  740         if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
  741                 struct ifaddr *ifa;
  742 
  743                 in6 = in6addr_loopback;
  744                 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &in6);
  745                 if (ifa == NULL) {
  746                         if (in6_ifattach_loopback(ifp) != 0)
  747                                 return;
  748                 } else
  749                         ifa_free(ifa);
  750         }
  751 
  752         /*
  753          * assign a link-local address, if there's none.
  754          */
  755         if (V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) {
  756                 ia = in6ifa_ifpforlinklocal(ifp, 0);
  757                 if (ia == NULL) {
  758                         if (in6_ifattach_linklocal(ifp, altifp) == 0) {
  759                                 /* linklocal address assigned */
  760                         } else {
  761                                 /* failed to assign linklocal address. bark? */
  762                         }
  763                 } else
  764                         ifa_free(&ia->ia_ifa);
  765         }
  766 
  767 #ifdef IFT_STF                  /* XXX */
  768 statinit:
  769 #endif
  770 
  771         /* update dynamically. */
  772         if (V_in6_maxmtu < ifp->if_mtu)
  773                 V_in6_maxmtu = ifp->if_mtu;
  774 }
  775 
  776 /*
  777  * NOTE: in6_ifdetach() does not support loopback if at this moment.
  778  * We don't need this function in bsdi, because interfaces are never removed
  779  * from the ifnet list in bsdi.
  780  */
  781 void
  782 in6_ifdetach(struct ifnet *ifp)
  783 {
  784         struct in6_ifaddr *ia;
  785         struct ifaddr *ifa, *next;
  786         struct radix_node_head *rnh;
  787         struct rtentry *rt;
  788         struct sockaddr_in6 sin6;
  789         struct in6_multi_mship *imm;
  790 
  791         /* remove neighbor management table */
  792         nd6_purge(ifp);
  793 
  794         /* nuke any of IPv6 addresses we have */
  795         TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
  796                 if (ifa->ifa_addr->sa_family != AF_INET6)
  797                         continue;
  798                 in6_purgeaddr(ifa);
  799         }
  800 
  801         /* undo everything done by in6_ifattach(), just in case */
  802         TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
  803                 if (ifa->ifa_addr->sa_family != AF_INET6
  804                  || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
  805                         continue;
  806                 }
  807 
  808                 ia = (struct in6_ifaddr *)ifa;
  809 
  810                 /*
  811                  * leave from multicast groups we have joined for the interface
  812                  */
  813                 while ((imm = LIST_FIRST(&ia->ia6_memberships)) != NULL) {
  814                         LIST_REMOVE(imm, i6mm_chain);
  815                         in6_leavegroup(imm);
  816                 }
  817 
  818                 /* Remove link-local from the routing table. */
  819                 if (ia->ia_flags & IFA_ROUTE)
  820                         (void)rtinit(&ia->ia_ifa, RTM_DELETE, ia->ia_flags);
  821 
  822                 /* remove from the linked list */
  823                 IF_ADDR_WLOCK(ifp);
  824                 TAILQ_REMOVE(&ifp->if_addrhead, ifa, ifa_link);
  825                 IF_ADDR_WUNLOCK(ifp);
  826                 ifa_free(ifa);                          /* if_addrhead */
  827 
  828                 IN6_IFADDR_WLOCK();
  829                 TAILQ_REMOVE(&V_in6_ifaddrhead, ia, ia_link);
  830                 IN6_IFADDR_WUNLOCK();
  831                 ifa_free(ifa);
  832         }
  833 
  834         in6_pcbpurgeif0(&V_udbinfo, ifp);
  835         in6_pcbpurgeif0(&V_ripcbinfo, ifp);
  836         /* leave from all multicast groups joined */
  837         in6_purgemaddrs(ifp);
  838 
  839         /*
  840          * remove neighbor management table.  we call it twice just to make
  841          * sure we nuke everything.  maybe we need just one call.
  842          * XXX: since the first call did not release addresses, some prefixes
  843          * might remain.  We should call nd6_purge() again to release the
  844          * prefixes after removing all addresses above.
  845          * (Or can we just delay calling nd6_purge until at this point?)
  846          */
  847         nd6_purge(ifp);
  848 
  849         /*
  850          * Remove route to link-local allnodes multicast (ff02::1).
  851          * These only get automatically installed for the default FIB.
  852          */
  853         bzero(&sin6, sizeof(sin6));
  854         sin6.sin6_len = sizeof(struct sockaddr_in6);
  855         sin6.sin6_family = AF_INET6;
  856         sin6.sin6_addr = in6addr_linklocal_allnodes;
  857         if (in6_setscope(&sin6.sin6_addr, ifp, NULL))
  858                 /* XXX: should not fail */
  859                 return;
  860         /* XXX grab lock first to avoid LOR */
  861         rnh = rt_tables_get_rnh(RT_DEFAULT_FIB, AF_INET6);
  862         if (rnh != NULL) {
  863                 RADIX_NODE_HEAD_LOCK(rnh);
  864                 rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, RTF_RNH_LOCKED,
  865                     RT_DEFAULT_FIB);
  866                 if (rt) {
  867                         if (rt->rt_ifp == ifp)
  868                                 rtexpunge(rt);
  869                         RTFREE_LOCKED(rt);
  870                 }
  871                 RADIX_NODE_HEAD_UNLOCK(rnh);
  872         }
  873 }
  874 
  875 int
  876 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf,
  877     const u_int8_t *baseid, int generate)
  878 {
  879         u_int8_t nullbuf[8];
  880         struct nd_ifinfo *ndi = ND_IFINFO(ifp);
  881 
  882         bzero(nullbuf, sizeof(nullbuf));
  883         if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
  884                 /* we've never created a random ID.  Create a new one. */
  885                 generate = 1;
  886         }
  887 
  888         if (generate) {
  889                 bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
  890 
  891                 /* generate_tmp_ifid will update seedn and buf */
  892                 (void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
  893                     ndi->randomid);
  894         }
  895         bcopy(ndi->randomid, retbuf, 8);
  896 
  897         return (0);
  898 }
  899 
  900 void
  901 in6_tmpaddrtimer(void *arg)
  902 {
  903         CURVNET_SET((struct vnet *) arg);
  904         struct nd_ifinfo *ndi;
  905         u_int8_t nullbuf[8];
  906         struct ifnet *ifp;
  907 
  908         callout_reset(&V_in6_tmpaddrtimer_ch,
  909             (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
  910             V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, curvnet);
  911 
  912         bzero(nullbuf, sizeof(nullbuf));
  913         TAILQ_FOREACH(ifp, &V_ifnet, if_list) {
  914                 ndi = ND_IFINFO(ifp);
  915                 if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
  916                         /*
  917                          * We've been generating a random ID on this interface.
  918                          * Create a new one.
  919                          */
  920                         (void)generate_tmp_ifid(ndi->randomseed0,
  921                             ndi->randomseed1, ndi->randomid);
  922                 }
  923         }
  924 
  925         CURVNET_RESTORE();
  926 }
  927 
  928 static void
  929 in6_purgemaddrs(struct ifnet *ifp)
  930 {
  931         LIST_HEAD(,in6_multi)    purgeinms;
  932         struct in6_multi        *inm, *tinm;
  933         struct ifmultiaddr      *ifma;
  934 
  935         LIST_INIT(&purgeinms);
  936         IN6_MULTI_LOCK();
  937 
  938         /*
  939          * Extract list of in6_multi associated with the detaching ifp
  940          * which the PF_INET6 layer is about to release.
  941          * We need to do this as IF_ADDR_LOCK() may be re-acquired
  942          * by code further down.
  943          */
  944         IF_ADDR_RLOCK(ifp);
  945         TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
  946                 if (ifma->ifma_addr->sa_family != AF_INET6 ||
  947                     ifma->ifma_protospec == NULL)
  948                         continue;
  949                 inm = (struct in6_multi *)ifma->ifma_protospec;
  950                 LIST_INSERT_HEAD(&purgeinms, inm, in6m_entry);
  951         }
  952         IF_ADDR_RUNLOCK(ifp);
  953 
  954         LIST_FOREACH_SAFE(inm, &purgeinms, in6m_entry, tinm) {
  955                 LIST_REMOVE(inm, in6m_entry);
  956                 in6m_release_locked(inm);
  957         }
  958         mld_ifdetach(ifp);
  959 
  960         IN6_MULTI_UNLOCK();
  961 }

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