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  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the project nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      $KAME: in6_ifattach.c,v 1.118 2001/05/24 07:44:00 itojun Exp $
   32  */
   33 
   34 #include <sys/cdefs.h>
   35 __FBSDID("$FreeBSD: releng/12.0/sys/netinet6/in6_ifattach.c 337866 2018-08-15 20:23:08Z mmacy $");
   36 
   37 #include <sys/param.h>
   38 #include <sys/systm.h>
   39 #include <sys/malloc.h>
   40 #include <sys/socket.h>
   41 #include <sys/sockio.h>
   42 #include <sys/jail.h>
   43 #include <sys/kernel.h>
   44 #include <sys/lock.h>
   45 #include <sys/proc.h>
   46 #include <sys/rmlock.h>
   47 #include <sys/syslog.h>
   48 #include <sys/md5.h>
   49 
   50 #include <net/if.h>
   51 #include <net/if_var.h>
   52 #include <net/if_dl.h>
   53 #include <net/if_types.h>
   54 #include <net/route.h>
   55 #include <net/vnet.h>
   56 
   57 #include <netinet/in.h>
   58 #include <netinet/in_var.h>
   59 #include <netinet/if_ether.h>
   60 #include <netinet/in_pcb.h>
   61 #include <netinet/ip_var.h>
   62 #include <netinet/udp.h>
   63 #include <netinet/udp_var.h>
   64 
   65 #include <netinet/ip6.h>
   66 #include <netinet6/ip6_var.h>
   67 #include <netinet6/in6_var.h>
   68 #include <netinet6/in6_pcb.h>
   69 #include <netinet6/in6_ifattach.h>
   70 #include <netinet6/ip6_var.h>
   71 #include <netinet6/nd6.h>
   72 #include <netinet6/mld6_var.h>
   73 #include <netinet6/scope6_var.h>
   74 
   75 VNET_DEFINE(unsigned long, in6_maxmtu) = 0;
   76 
   77 #ifdef IP6_AUTO_LINKLOCAL
   78 VNET_DEFINE(int, ip6_auto_linklocal) = IP6_AUTO_LINKLOCAL;
   79 #else
   80 VNET_DEFINE(int, ip6_auto_linklocal) = 1;       /* enabled by default */
   81 #endif
   82 
   83 VNET_DEFINE(struct callout, in6_tmpaddrtimer_ch);
   84 #define V_in6_tmpaddrtimer_ch           VNET(in6_tmpaddrtimer_ch)
   85 
   86 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
   87 #define V_ripcbinfo                     VNET(ripcbinfo)
   88 
   89 static int get_rand_ifid(struct ifnet *, struct in6_addr *);
   90 static int generate_tmp_ifid(u_int8_t *, const u_int8_t *, u_int8_t *);
   91 static int get_ifid(struct ifnet *, struct ifnet *, struct in6_addr *);
   92 static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *);
   93 static int in6_ifattach_loopback(struct ifnet *);
   94 static void in6_purgemaddrs(struct ifnet *);
   95 
   96 #define EUI64_GBIT      0x01
   97 #define EUI64_UBIT      0x02
   98 #define EUI64_TO_IFID(in6)      do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
   99 #define EUI64_GROUP(in6)        ((in6)->s6_addr[8] & EUI64_GBIT)
  100 #define EUI64_INDIVIDUAL(in6)   (!EUI64_GROUP(in6))
  101 #define EUI64_LOCAL(in6)        ((in6)->s6_addr[8] & EUI64_UBIT)
  102 #define EUI64_UNIVERSAL(in6)    (!EUI64_LOCAL(in6))
  103 
  104 #define IFID_LOCAL(in6)         (!EUI64_LOCAL(in6))
  105 #define IFID_UNIVERSAL(in6)     (!EUI64_UNIVERSAL(in6))
  106 
  107 /*
  108  * Generate a last-resort interface identifier, when the machine has no
  109  * IEEE802/EUI64 address sources.
  110  * The goal here is to get an interface identifier that is
  111  * (1) random enough and (2) does not change across reboot.
  112  * We currently use MD5(hostname) for it.
  113  *
  114  * in6 - upper 64bits are preserved
  115  */
  116 static int
  117 get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
  118 {
  119         MD5_CTX ctxt;
  120         struct prison *pr;
  121         u_int8_t digest[16];
  122         int hostnamelen;
  123 
  124         pr = curthread->td_ucred->cr_prison;
  125         mtx_lock(&pr->pr_mtx);
  126         hostnamelen = strlen(pr->pr_hostname);
  127 #if 0
  128         /* we need at least several letters as seed for ifid */
  129         if (hostnamelen < 3) {
  130                 mtx_unlock(&pr->pr_mtx);
  131                 return -1;
  132         }
  133 #endif
  134 
  135         /* generate 8 bytes of pseudo-random value. */
  136         bzero(&ctxt, sizeof(ctxt));
  137         MD5Init(&ctxt);
  138         MD5Update(&ctxt, pr->pr_hostname, hostnamelen);
  139         mtx_unlock(&pr->pr_mtx);
  140         MD5Final(digest, &ctxt);
  141 
  142         /* assumes sizeof(digest) > sizeof(ifid) */
  143         bcopy(digest, &in6->s6_addr[8], 8);
  144 
  145         /* make sure to set "u" bit to local, and "g" bit to individual. */
  146         in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
  147         in6->s6_addr[8] |= EUI64_UBIT;  /* u bit to "local" */
  148 
  149         /* convert EUI64 into IPv6 interface identifier */
  150         EUI64_TO_IFID(in6);
  151 
  152         return 0;
  153 }
  154 
  155 static int
  156 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
  157 {
  158         MD5_CTX ctxt;
  159         u_int8_t seed[16], digest[16], nullbuf[8];
  160         u_int32_t val32;
  161 
  162         /* If there's no history, start with a random seed. */
  163         bzero(nullbuf, sizeof(nullbuf));
  164         if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
  165                 int i;
  166 
  167                 for (i = 0; i < 2; i++) {
  168                         val32 = arc4random();
  169                         bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
  170                 }
  171         } else
  172                 bcopy(seed0, seed, 8);
  173 
  174         /* copy the right-most 64-bits of the given address */
  175         /* XXX assumption on the size of IFID */
  176         bcopy(seed1, &seed[8], 8);
  177 
  178         if (0) {                /* for debugging purposes only */
  179                 int i;
  180 
  181                 printf("generate_tmp_ifid: new randomized ID from: ");
  182                 for (i = 0; i < 16; i++)
  183                         printf("%02x", seed[i]);
  184                 printf(" ");
  185         }
  186 
  187         /* generate 16 bytes of pseudo-random value. */
  188         bzero(&ctxt, sizeof(ctxt));
  189         MD5Init(&ctxt);
  190         MD5Update(&ctxt, seed, sizeof(seed));
  191         MD5Final(digest, &ctxt);
  192 
  193         /*
  194          * RFC 3041 3.2.1. (3)
  195          * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
  196          * left-most bit is numbered 0) to zero.
  197          */
  198         bcopy(digest, ret, 8);
  199         ret[0] &= ~EUI64_UBIT;
  200 
  201         /*
  202          * XXX: we'd like to ensure that the generated value is not zero
  203          * for simplicity.  If the caclculated digest happens to be zero,
  204          * use a random non-zero value as the last resort.
  205          */
  206         if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
  207                 nd6log((LOG_INFO,
  208                     "generate_tmp_ifid: computed MD5 value is zero.\n"));
  209 
  210                 val32 = arc4random();
  211                 val32 = 1 + (val32 % (0xffffffff - 1));
  212         }
  213 
  214         /*
  215          * RFC 3041 3.2.1. (4)
  216          * Take the rightmost 64-bits of the MD5 digest and save them in
  217          * stable storage as the history value to be used in the next
  218          * iteration of the algorithm.
  219          */
  220         bcopy(&digest[8], seed0, 8);
  221 
  222         if (0) {                /* for debugging purposes only */
  223                 int i;
  224 
  225                 printf("to: ");
  226                 for (i = 0; i < 16; i++)
  227                         printf("%02x", digest[i]);
  228                 printf("\n");
  229         }
  230 
  231         return 0;
  232 }
  233 
  234 /*
  235  * Get interface identifier for the specified interface.
  236  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
  237  *
  238  * in6 - upper 64bits are preserved
  239  */
  240 int
  241 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
  242 {
  243         struct ifaddr *ifa;
  244         struct sockaddr_dl *sdl;
  245         u_int8_t *addr;
  246         size_t addrlen;
  247         static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
  248         static u_int8_t allone[8] =
  249                 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  250 
  251         IF_ADDR_RLOCK(ifp);
  252         CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
  253                 if (ifa->ifa_addr->sa_family != AF_LINK)
  254                         continue;
  255                 sdl = (struct sockaddr_dl *)ifa->ifa_addr;
  256                 if (sdl == NULL)
  257                         continue;
  258                 if (sdl->sdl_alen == 0)
  259                         continue;
  260 
  261                 goto found;
  262         }
  263         IF_ADDR_RUNLOCK(ifp);
  264 
  265         return -1;
  266 
  267 found:
  268         IF_ADDR_LOCK_ASSERT(ifp);
  269         addr = LLADDR(sdl);
  270         addrlen = sdl->sdl_alen;
  271 
  272         /* get EUI64 */
  273         switch (ifp->if_type) {
  274         case IFT_BRIDGE:
  275         case IFT_ETHER:
  276         case IFT_L2VLAN:
  277         case IFT_ATM:
  278         case IFT_IEEE1394:
  279                 /* IEEE802/EUI64 cases - what others? */
  280                 /* IEEE1394 uses 16byte length address starting with EUI64 */
  281                 if (addrlen > 8)
  282                         addrlen = 8;
  283 
  284                 /* look at IEEE802/EUI64 only */
  285                 if (addrlen != 8 && addrlen != 6) {
  286                         IF_ADDR_RUNLOCK(ifp);
  287                         return -1;
  288                 }
  289 
  290                 /*
  291                  * check for invalid MAC address - on bsdi, we see it a lot
  292                  * since wildboar configures all-zero MAC on pccard before
  293                  * card insertion.
  294                  */
  295                 if (bcmp(addr, allzero, addrlen) == 0) {
  296                         IF_ADDR_RUNLOCK(ifp);
  297                         return -1;
  298                 }
  299                 if (bcmp(addr, allone, addrlen) == 0) {
  300                         IF_ADDR_RUNLOCK(ifp);
  301                         return -1;
  302                 }
  303 
  304                 /* make EUI64 address */
  305                 if (addrlen == 8)
  306                         bcopy(addr, &in6->s6_addr[8], 8);
  307                 else if (addrlen == 6) {
  308                         in6->s6_addr[8] = addr[0];
  309                         in6->s6_addr[9] = addr[1];
  310                         in6->s6_addr[10] = addr[2];
  311                         in6->s6_addr[11] = 0xff;
  312                         in6->s6_addr[12] = 0xfe;
  313                         in6->s6_addr[13] = addr[3];
  314                         in6->s6_addr[14] = addr[4];
  315                         in6->s6_addr[15] = addr[5];
  316                 }
  317                 break;
  318 
  319         case IFT_GIF:
  320         case IFT_STF:
  321                 /*
  322                  * RFC2893 says: "SHOULD use IPv4 address as ifid source".
  323                  * however, IPv4 address is not very suitable as unique
  324                  * identifier source (can be renumbered).
  325                  * we don't do this.
  326                  */
  327                 IF_ADDR_RUNLOCK(ifp);
  328                 return -1;
  329 
  330         default:
  331                 IF_ADDR_RUNLOCK(ifp);
  332                 return -1;
  333         }
  334 
  335         /* sanity check: g bit must not indicate "group" */
  336         if (EUI64_GROUP(in6)) {
  337                 IF_ADDR_RUNLOCK(ifp);
  338                 return -1;
  339         }
  340 
  341         /* convert EUI64 into IPv6 interface identifier */
  342         EUI64_TO_IFID(in6);
  343 
  344         /*
  345          * sanity check: ifid must not be all zero, avoid conflict with
  346          * subnet router anycast
  347          */
  348         if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
  349             bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
  350                 IF_ADDR_RUNLOCK(ifp);
  351                 return -1;
  352         }
  353 
  354         IF_ADDR_RUNLOCK(ifp);
  355         return 0;
  356 }
  357 
  358 /*
  359  * Get interface identifier for the specified interface.  If it is not
  360  * available on ifp0, borrow interface identifier from other information
  361  * sources.
  362  *
  363  * altifp - secondary EUI64 source
  364  */
  365 static int
  366 get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
  367     struct in6_addr *in6)
  368 {
  369         struct ifnet *ifp;
  370 
  371         /* first, try to get it from the interface itself */
  372         if (in6_get_hw_ifid(ifp0, in6) == 0) {
  373                 nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
  374                     if_name(ifp0)));
  375                 goto success;
  376         }
  377 
  378         /* try secondary EUI64 source. this basically is for ATM PVC */
  379         if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
  380                 nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
  381                     if_name(ifp0), if_name(altifp)));
  382                 goto success;
  383         }
  384 
  385         /* next, try to get it from some other hardware interface */
  386         IFNET_RLOCK_NOSLEEP();
  387         CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
  388                 if (ifp == ifp0)
  389                         continue;
  390                 if (in6_get_hw_ifid(ifp, in6) != 0)
  391                         continue;
  392 
  393                 /*
  394                  * to borrow ifid from other interface, ifid needs to be
  395                  * globally unique
  396                  */
  397                 if (IFID_UNIVERSAL(in6)) {
  398                         nd6log((LOG_DEBUG,
  399                             "%s: borrow interface identifier from %s\n",
  400                             if_name(ifp0), if_name(ifp)));
  401                         IFNET_RUNLOCK_NOSLEEP();
  402                         goto success;
  403                 }
  404         }
  405         IFNET_RUNLOCK_NOSLEEP();
  406 
  407         /* last resort: get from random number source */
  408         if (get_rand_ifid(ifp, in6) == 0) {
  409                 nd6log((LOG_DEBUG,
  410                     "%s: interface identifier generated by random number\n",
  411                     if_name(ifp0)));
  412                 goto success;
  413         }
  414 
  415         printf("%s: failed to get interface identifier\n", if_name(ifp0));
  416         return -1;
  417 
  418 success:
  419         nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
  420             if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
  421             in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
  422             in6->s6_addr[14], in6->s6_addr[15]));
  423         return 0;
  424 }
  425 
  426 /*
  427  * altifp - secondary EUI64 source
  428  */
  429 static int
  430 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
  431 {
  432         struct in6_ifaddr *ia;
  433         struct in6_aliasreq ifra;
  434         struct nd_prefixctl pr0;
  435         struct nd_prefix *pr;
  436         int error;
  437 
  438         /*
  439          * configure link-local address.
  440          */
  441         in6_prepare_ifra(&ifra, NULL, &in6mask64);
  442 
  443         ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
  444         ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
  445         if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
  446                 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
  447                 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
  448         } else {
  449                 if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
  450                         nd6log((LOG_ERR,
  451                             "%s: no ifid available\n", if_name(ifp)));
  452                         return (-1);
  453                 }
  454         }
  455         if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
  456                 return (-1);
  457 
  458         /* link-local addresses should NEVER expire. */
  459         ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
  460         ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
  461 
  462         /*
  463          * Now call in6_update_ifa() to do a bunch of procedures to configure
  464          * a link-local address. We can set the 3rd argument to NULL, because
  465          * we know there's no other link-local address on the interface
  466          * and therefore we are adding one (instead of updating one).
  467          */
  468         if ((error = in6_update_ifa(ifp, &ifra, NULL,
  469                                     IN6_IFAUPDATE_DADDELAY)) != 0) {
  470                 /*
  471                  * XXX: When the interface does not support IPv6, this call
  472                  * would fail in the SIOCSIFADDR ioctl.  I believe the
  473                  * notification is rather confusing in this case, so just
  474                  * suppress it.  (jinmei@kame.net 20010130)
  475                  */
  476                 if (error != EAFNOSUPPORT)
  477                         nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
  478                             "configure a link-local address on %s "
  479                             "(errno=%d)\n",
  480                             if_name(ifp), error));
  481                 return (-1);
  482         }
  483 
  484         ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
  485         KASSERT(ia != NULL, ("%s: ia == NULL, ifp=%p", __func__, ifp));
  486 
  487         ifa_free(&ia->ia_ifa);
  488 
  489         /*
  490          * Make the link-local prefix (fe80::%link/64) as on-link.
  491          * Since we'd like to manage prefixes separately from addresses,
  492          * we make an ND6 prefix structure for the link-local prefix,
  493          * and add it to the prefix list as a never-expire prefix.
  494          * XXX: this change might affect some existing code base...
  495          */
  496         bzero(&pr0, sizeof(pr0));
  497         pr0.ndpr_ifp = ifp;
  498         /* this should be 64 at this moment. */
  499         pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
  500         pr0.ndpr_prefix = ifra.ifra_addr;
  501         /* apply the mask for safety. (nd6_prelist_add will apply it again) */
  502         IN6_MASK_ADDR(&pr0.ndpr_prefix.sin6_addr, &in6mask64);
  503         /*
  504          * Initialize parameters.  The link-local prefix must always be
  505          * on-link, and its lifetimes never expire.
  506          */
  507         pr0.ndpr_raf_onlink = 1;
  508         pr0.ndpr_raf_auto = 1;  /* probably meaningless */
  509         pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
  510         pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
  511         /*
  512          * Since there is no other link-local addresses, nd6_prefix_lookup()
  513          * probably returns NULL.  However, we cannot always expect the result.
  514          * For example, if we first remove the (only) existing link-local
  515          * address, and then reconfigure another one, the prefix is still
  516          * valid with referring to the old link-local address.
  517          */
  518         if ((pr = nd6_prefix_lookup(&pr0)) == NULL) {
  519                 if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
  520                         return (error);
  521         } else
  522                 nd6_prefix_rele(pr);
  523 
  524         return 0;
  525 }
  526 
  527 /*
  528  * ifp - must be IFT_LOOP
  529  */
  530 static int
  531 in6_ifattach_loopback(struct ifnet *ifp)
  532 {
  533         struct in6_aliasreq ifra;
  534         int error;
  535 
  536         in6_prepare_ifra(&ifra, &in6addr_loopback, &in6mask128);
  537 
  538         /*
  539          * Always initialize ia_dstaddr (= broadcast address) to loopback
  540          * address.  Follows IPv4 practice - see in_ifinit().
  541          */
  542         ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
  543         ifra.ifra_dstaddr.sin6_family = AF_INET6;
  544         ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
  545 
  546         /* the loopback  address should NEVER expire. */
  547         ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
  548         ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
  549 
  550         /*
  551          * We are sure that this is a newly assigned address, so we can set
  552          * NULL to the 3rd arg.
  553          */
  554         if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
  555                 nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
  556                     "the loopback address on %s (errno=%d)\n",
  557                     if_name(ifp), error));
  558                 return (-1);
  559         }
  560 
  561         return 0;
  562 }
  563 
  564 /*
  565  * compute NI group address, based on the current hostname setting.
  566  * see RFC 4620.
  567  *
  568  * when ifp == NULL, the caller is responsible for filling scopeid.
  569  *
  570  * If oldmcprefix == 1, FF02:0:0:0:0:2::/96 is used for NI group address
  571  * while it is FF02:0:0:0:0:2:FF00::/104 in RFC 4620. 
  572  */
  573 static int
  574 in6_nigroup0(struct ifnet *ifp, const char *name, int namelen,
  575     struct in6_addr *in6, int oldmcprefix)
  576 {
  577         struct prison *pr;
  578         const char *p;
  579         u_char *q;
  580         MD5_CTX ctxt;
  581         u_int8_t digest[16];
  582         char l;
  583         char n[64];     /* a single label must not exceed 63 chars */
  584 
  585         /*
  586          * If no name is given and namelen is -1,
  587          * we try to do the hostname lookup ourselves.
  588          */
  589         if (!name && namelen == -1) {
  590                 pr = curthread->td_ucred->cr_prison;
  591                 mtx_lock(&pr->pr_mtx);
  592                 name = pr->pr_hostname;
  593                 namelen = strlen(name);
  594         } else
  595                 pr = NULL;
  596         if (!name || !namelen) {
  597                 if (pr != NULL)
  598                         mtx_unlock(&pr->pr_mtx);
  599                 return -1;
  600         }
  601 
  602         p = name;
  603         while (p && *p && *p != '.' && p - name < namelen)
  604                 p++;
  605         if (p == name || p - name > sizeof(n) - 1) {
  606                 if (pr != NULL)
  607                         mtx_unlock(&pr->pr_mtx);
  608                 return -1;      /* label too long */
  609         }
  610         l = p - name;
  611         strncpy(n, name, l);
  612         if (pr != NULL)
  613                 mtx_unlock(&pr->pr_mtx);
  614         n[(int)l] = '\0';
  615         for (q = n; *q; q++) {
  616                 if ('A' <= *q && *q <= 'Z')
  617                         *q = *q - 'A' + 'a';
  618         }
  619 
  620         /* generate 16 bytes of pseudo-random value. */
  621         bzero(&ctxt, sizeof(ctxt));
  622         MD5Init(&ctxt);
  623         MD5Update(&ctxt, &l, sizeof(l));
  624         MD5Update(&ctxt, n, l);
  625         MD5Final(digest, &ctxt);
  626 
  627         bzero(in6, sizeof(*in6));
  628         in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  629         in6->s6_addr8[11] = 2;
  630         if (oldmcprefix == 0) {
  631                 in6->s6_addr8[12] = 0xff;
  632                 /* Copy the first 24 bits of 128-bit hash into the address. */
  633                 bcopy(digest, &in6->s6_addr8[13], 3);
  634         } else {
  635                 /* Copy the first 32 bits of 128-bit hash into the address. */
  636                 bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
  637         }
  638         if (in6_setscope(in6, ifp, NULL))
  639                 return (-1); /* XXX: should not fail */
  640 
  641         return 0;
  642 }
  643 
  644 int
  645 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
  646     struct in6_addr *in6)
  647 {
  648 
  649         return (in6_nigroup0(ifp, name, namelen, in6, 0));
  650 }
  651 
  652 int
  653 in6_nigroup_oldmcprefix(struct ifnet *ifp, const char *name, int namelen,
  654     struct in6_addr *in6)
  655 {
  656 
  657         return (in6_nigroup0(ifp, name, namelen, in6, 1));
  658 }
  659 
  660 /*
  661  * XXX multiple loopback interface needs more care.  for instance,
  662  * nodelocal address needs to be configured onto only one of them.
  663  * XXX multiple link-local address case
  664  *
  665  * altifp - secondary EUI64 source
  666  */
  667 void
  668 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
  669 {
  670         struct in6_ifaddr *ia;
  671 
  672         if (ifp->if_afdata[AF_INET6] == NULL)
  673                 return;
  674         /*
  675          * quirks based on interface type
  676          */
  677         switch (ifp->if_type) {
  678         case IFT_STF:
  679                 /*
  680                  * 6to4 interface is a very special kind of beast.
  681                  * no multicast, no linklocal.  RFC2529 specifies how to make
  682                  * linklocals for 6to4 interface, but there's no use and
  683                  * it is rather harmful to have one.
  684                  */
  685                 ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
  686                 break;
  687         default:
  688                 break;
  689         }
  690 
  691         /*
  692          * usually, we require multicast capability to the interface
  693          */
  694         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
  695                 nd6log((LOG_INFO, "in6_ifattach: "
  696                     "%s is not multicast capable, IPv6 not enabled\n",
  697                     if_name(ifp)));
  698                 return;
  699         }
  700 
  701         /*
  702          * assign loopback address for loopback interface.
  703          */
  704         if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
  705                 /*
  706                  * check that loopback address doesn't exist yet.
  707                  */
  708                 ia = in6ifa_ifwithaddr(&in6addr_loopback, 0);
  709                 if (ia == NULL)
  710                         in6_ifattach_loopback(ifp);
  711                 else
  712                         ifa_free(&ia->ia_ifa);
  713         }
  714 
  715         /*
  716          * assign a link-local address, if there's none.
  717          */
  718         if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
  719             ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) {
  720                 ia = in6ifa_ifpforlinklocal(ifp, 0);
  721                 if (ia == NULL)
  722                         in6_ifattach_linklocal(ifp, altifp);
  723                 else
  724                         ifa_free(&ia->ia_ifa);
  725         }
  726 
  727         /* update dynamically. */
  728         if (V_in6_maxmtu < ifp->if_mtu)
  729                 V_in6_maxmtu = ifp->if_mtu;
  730 }
  731 
  732 /*
  733  * NOTE: in6_ifdetach() does not support loopback if at this moment.
  734  *
  735  * When shutting down a VNET we clean up layers top-down.  In that case
  736  * upper layer protocols (ulp) are cleaned up already and locks are destroyed
  737  * and we must not call into these cleanup functions anymore, thus purgeulp
  738  * is set to 0 in that case by in6_ifdetach_destroy().
  739  * The normal case of destroying a (cloned) interface still needs to cleanup
  740  * everything related to the interface and will have purgeulp set to 1.
  741  */
  742 static void
  743 _in6_ifdetach(struct ifnet *ifp, int purgeulp)
  744 {
  745         struct ifaddr *ifa, *next;
  746 
  747         if (ifp->if_afdata[AF_INET6] == NULL)
  748                 return;
  749 
  750         /*
  751          * nuke any of IPv6 addresses we have
  752          */
  753         CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
  754                 if (ifa->ifa_addr->sa_family != AF_INET6)
  755                         continue;
  756                 in6_purgeaddr(ifa);
  757         }
  758         if (purgeulp) {
  759                 in6_pcbpurgeif0(&V_udbinfo, ifp);
  760                 in6_pcbpurgeif0(&V_ulitecbinfo, ifp);
  761                 in6_pcbpurgeif0(&V_ripcbinfo, ifp);
  762         }
  763         /* leave from all multicast groups joined */
  764         in6_purgemaddrs(ifp);
  765 
  766         /*
  767          * Remove neighbor management table.
  768          * Enabling the nd6_purge will panic on vmove for interfaces on VNET
  769          * teardown as the IPv6 layer is cleaned up already and the locks
  770          * are destroyed.
  771          */
  772         if (purgeulp)
  773                 nd6_purge(ifp);
  774 }
  775 
  776 void
  777 in6_ifdetach(struct ifnet *ifp)
  778 {
  779 
  780         _in6_ifdetach(ifp, 1);
  781 }
  782 
  783 void
  784 in6_ifdetach_destroy(struct ifnet *ifp)
  785 {
  786 
  787         _in6_ifdetach(ifp, 0);
  788 }
  789 
  790 int
  791 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf,
  792     const u_int8_t *baseid, int generate)
  793 {
  794         u_int8_t nullbuf[8];
  795         struct nd_ifinfo *ndi = ND_IFINFO(ifp);
  796 
  797         bzero(nullbuf, sizeof(nullbuf));
  798         if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
  799                 /* we've never created a random ID.  Create a new one. */
  800                 generate = 1;
  801         }
  802 
  803         if (generate) {
  804                 bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
  805 
  806                 /* generate_tmp_ifid will update seedn and buf */
  807                 (void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
  808                     ndi->randomid);
  809         }
  810         bcopy(ndi->randomid, retbuf, 8);
  811 
  812         return (0);
  813 }
  814 
  815 void
  816 in6_tmpaddrtimer(void *arg)
  817 {
  818         CURVNET_SET((struct vnet *) arg);
  819         struct nd_ifinfo *ndi;
  820         u_int8_t nullbuf[8];
  821         struct ifnet *ifp;
  822 
  823         callout_reset(&V_in6_tmpaddrtimer_ch,
  824             (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
  825             V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, curvnet);
  826 
  827         bzero(nullbuf, sizeof(nullbuf));
  828         CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
  829                 if (ifp->if_afdata[AF_INET6] == NULL)
  830                         continue;
  831                 ndi = ND_IFINFO(ifp);
  832                 if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
  833                         /*
  834                          * We've been generating a random ID on this interface.
  835                          * Create a new one.
  836                          */
  837                         (void)generate_tmp_ifid(ndi->randomseed0,
  838                             ndi->randomseed1, ndi->randomid);
  839                 }
  840         }
  841 
  842         CURVNET_RESTORE();
  843 }
  844 
  845 static void
  846 in6_purgemaddrs(struct ifnet *ifp)
  847 {
  848         struct in6_multi_head    purgeinms;
  849         struct in6_multi        *inm;
  850         struct ifmultiaddr      *ifma, *next;
  851 
  852         SLIST_INIT(&purgeinms);
  853         IN6_MULTI_LOCK();
  854         IN6_MULTI_LIST_LOCK();
  855         IF_ADDR_WLOCK(ifp);
  856         /*
  857          * Extract list of in6_multi associated with the detaching ifp
  858          * which the PF_INET6 layer is about to release.
  859          */
  860  restart:
  861         CK_STAILQ_FOREACH_SAFE(ifma, &ifp->if_multiaddrs, ifma_link, next) {
  862                 if (ifma->ifma_addr->sa_family != AF_INET6 ||
  863                     ifma->ifma_protospec == NULL)
  864                         continue;
  865                 inm = (struct in6_multi *)ifma->ifma_protospec;
  866                 in6m_disconnect(inm);
  867                 in6m_rele_locked(&purgeinms, inm);
  868                 if (__predict_false(ifma6_restart)) {
  869                         ifma6_restart = false;
  870                         goto restart;
  871                 }
  872         }
  873         IF_ADDR_WUNLOCK(ifp);
  874         mld_ifdetach(ifp);
  875         IN6_MULTI_LIST_UNLOCK();
  876         IN6_MULTI_UNLOCK();
  877         in6m_release_list_deferred(&purgeinms);
  878 }
  879 
  880 void
  881 in6_ifattach_destroy(void)
  882 {
  883 
  884         callout_drain(&V_in6_tmpaddrtimer_ch);
  885 }
  886 
  887 static void
  888 in6_ifattach_init(void *dummy)
  889 {
  890 
  891         /* Timer for regeneranation of temporary addresses randomize ID. */
  892         callout_init(&V_in6_tmpaddrtimer_ch, 0);
  893         callout_reset(&V_in6_tmpaddrtimer_ch,
  894             (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
  895             V_ip6_temp_regen_advance) * hz,
  896             in6_tmpaddrtimer, curvnet);
  897 }
  898 
  899 /*
  900  * Cheat.
  901  * This must be after route_init(), which is now SI_ORDER_THIRD.
  902  */
  903 SYSINIT(in6_ifattach_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
  904     in6_ifattach_init, NULL);

Cache object: 288ae40f446490e4e35f905ead2ecd3a


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