net/ipv6/ndisc.c

   1 /*
   2  *      Neighbour Discovery for IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *      Mike Shaver             <shaver@ingenia.com>
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License
  11  *      as published by the Free Software Foundation; either version
  12  *      2 of the License, or (at your option) any later version.
  13  */
  14
  15 /*
  16  *      Changes:
  17  *
  18  *      Pierre Ynard                    :       export userland ND options
  19  *                                              through netlink (RDNSS support)
  20  *      Lars Fenneberg                  :       fixed MTU setting on receipt
  21  *                                              of an RA.
  22  *      Janos Farkas                    :       kmalloc failure checks
  23  *      Alexey Kuznetsov                :       state machine reworked
  24  *                                              and moved to net/core.
  25  *      Pekka Savola                    :       RFC2461 validation
  26  *      YOSHIFUJI Hideaki @USAGI        :       Verify ND options properly
  27  */
  28
  29 /* Set to 3 to get tracing... */
  30 #define ND_DEBUG 1
  31
  32 #define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0)
  33 #define ND_NOPRINTK(x...) do { ; } while(0)
  34 #define ND_PRINTK0 ND_PRINTK
  35 #define ND_PRINTK1 ND_NOPRINTK
  36 #define ND_PRINTK2 ND_NOPRINTK
  37 #define ND_PRINTK3 ND_NOPRINTK
  38 #if ND_DEBUG >= 1
  39 #undef ND_PRINTK1
  40 #define ND_PRINTK1 ND_PRINTK
  41 #endif
  42 #if ND_DEBUG >= 2
  43 #undef ND_PRINTK2
  44 #define ND_PRINTK2 ND_PRINTK
  45 #endif
  46 #if ND_DEBUG >= 3
  47 #undef ND_PRINTK3
  48 #define ND_PRINTK3 ND_PRINTK
  49 #endif
  50
  51 #include <linux/module.h>
  52 #include <linux/errno.h>
  53 #include <linux/types.h>
  54 #include <linux/socket.h>
  55 #include <linux/sockios.h>
  56 #include <linux/sched.h>
  57 #include <linux/net.h>
  58 #include <linux/in6.h>
  59 #include <linux/route.h>
  60 #include <linux/init.h>
  61 #include <linux/rcupdate.h>
  62 #include <linux/slab.h>
  63 #ifdef CONFIG_SYSCTL
  64 #include <linux/sysctl.h>
  65 #endif
  66
  67 #include <linux/if_addr.h>
  68 #include <linux/if_arp.h>
  69 #include <linux/ipv6.h>
  70 #include <linux/icmpv6.h>
  71 #include <linux/jhash.h>
  72
  73 #include <net/sock.h>
  74 #include <net/snmp.h>
  75
  76 #include <net/ipv6.h>
  77 #include <net/protocol.h>
  78 #include <net/ndisc.h>
  79 #include <net/ip6_route.h>
  80 #include <net/addrconf.h>
  81 #include <net/icmp.h>
  82
  83 #include <net/netlink.h>
  84 #include <linux/rtnetlink.h>
  85
  86 #include <net/flow.h>
  87 #include <net/ip6_checksum.h>
  88 #include <net/inet_common.h>
  89 #include <linux/proc_fs.h>
  90
  91 #include <linux/netfilter.h>
  92 #include <linux/netfilter_ipv6.h>
  93
  94 static u32 ndisc_hash(const void *pkey, const struct net_device *dev);
  95 static int ndisc_constructor(struct neighbour *neigh);
  96 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
  97 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
  98 static int pndisc_constructor(struct pneigh_entry *n);
  99 static void pndisc_destructor(struct pneigh_entry *n);
 100 static void pndisc_redo(struct sk_buff *skb);
 101
 102 static const struct neigh_ops ndisc_generic_ops = {
 103         .family =               AF_INET6,
 104         .solicit =              ndisc_solicit,
 105         .error_report =         ndisc_error_report,
 106         .output =               neigh_resolve_output,
 107         .connected_output =     neigh_connected_output,
 108         .hh_output =            dev_queue_xmit,
 109         .queue_xmit =           dev_queue_xmit,
 110 };
 111
 112 static const struct neigh_ops ndisc_hh_ops = {
 113         .family =               AF_INET6,
 114         .solicit =              ndisc_solicit,
 115         .error_report =         ndisc_error_report,
 116         .output =               neigh_resolve_output,
 117         .connected_output =     neigh_resolve_output,
 118         .hh_output =            dev_queue_xmit,
 119         .queue_xmit =           dev_queue_xmit,
 120 };
 121
 122
 123 static const struct neigh_ops ndisc_direct_ops = {
 124         .family =               AF_INET6,
 125         .output =               dev_queue_xmit,
 126         .connected_output =     dev_queue_xmit,
 127         .hh_output =            dev_queue_xmit,
 128         .queue_xmit =           dev_queue_xmit,
 129 };
 130
 131 struct neigh_table nd_tbl = {
 132         .family =       AF_INET6,
 133         .entry_size =   sizeof(struct neighbour) + sizeof(struct in6_addr),
 134         .key_len =      sizeof(struct in6_addr),
 135         .hash =         ndisc_hash,
 136         .constructor =  ndisc_constructor,
 137         .pconstructor = pndisc_constructor,
 138         .pdestructor =  pndisc_destructor,
 139         .proxy_redo =   pndisc_redo,
 140         .id =           "ndisc_cache",
 141         .parms = {
 142                 .tbl =                  &nd_tbl,
 143                 .base_reachable_time =  30 * HZ,
 144                 .retrans_time =  1 * HZ,
 145                 .gc_staletime = 60 * HZ,
 146                 .reachable_time =               30 * HZ,
 147                 .delay_probe_time =      5 * HZ,
 148                 .queue_len =             3,
 149                 .ucast_probes =  3,
 150                 .mcast_probes =  3,
 151                 .anycast_delay =         1 * HZ,
 152                 .proxy_delay =          (8 * HZ) / 10,
 153                 .proxy_qlen =           64,
 154         },
 155         .gc_interval =    30 * HZ,
 156         .gc_thresh1 =    128,
 157         .gc_thresh2 =    512,
 158         .gc_thresh3 =   1024,
 159 };
 160
 161 /* ND options */
 162 struct ndisc_options {
 163         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 164 #ifdef CONFIG_IPV6_ROUTE_INFO
 165         struct nd_opt_hdr *nd_opts_ri;
 166         struct nd_opt_hdr *nd_opts_ri_end;
 167 #endif
 168         struct nd_opt_hdr *nd_useropts;
 169         struct nd_opt_hdr *nd_useropts_end;
 170 };
 171
 172 #define nd_opts_src_lladdr      nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
 173 #define nd_opts_tgt_lladdr      nd_opt_array[ND_OPT_TARGET_LL_ADDR]
 174 #define nd_opts_pi              nd_opt_array[ND_OPT_PREFIX_INFO]
 175 #define nd_opts_pi_end          nd_opt_array[__ND_OPT_PREFIX_INFO_END]
 176 #define nd_opts_rh              nd_opt_array[ND_OPT_REDIRECT_HDR]
 177 #define nd_opts_mtu             nd_opt_array[ND_OPT_MTU]
 178
 179 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 180
 181 /*
 182  * Return the padding between the option length and the start of the
 183  * link addr.  Currently only IP-over-InfiniBand needs this, although
 184  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 185  * also need a pad of 2.
 186  */
 187 static int ndisc_addr_option_pad(unsigned short type)
 188 {
 189         switch (type) {
 190         case ARPHRD_INFINIBAND: return 2;
 191         default:                return 0;
 192         }
 193 }
 194
 195 static inline int ndisc_opt_addr_space(struct net_device *dev)
 196 {
 197         return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
 198 }
 199
 200 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
 201                                   unsigned short addr_type)
 202 {
 203         int space = NDISC_OPT_SPACE(data_len);
 204         int pad   = ndisc_addr_option_pad(addr_type);
 205
 206         opt[0] = type;
 207         opt[1] = space>>3;
 208
 209         memset(opt + 2, 0, pad);
 210         opt   += pad;
 211         space -= pad;
 212
 213         memcpy(opt+2, data, data_len);
 214         data_len += 2;
 215         opt += data_len;
 216         if ((space -= data_len) > 0)
 217                 memset(opt, 0, space);
 218         return opt + space;
 219 }
 220
 221 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 222                                             struct nd_opt_hdr *end)
 223 {
 224         int type;
 225         if (!cur || !end || cur >= end)
 226                 return NULL;
 227         type = cur->nd_opt_type;
 228         do {
 229                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
 230         } while(cur < end && cur->nd_opt_type != type);
 231         return (cur <= end && cur->nd_opt_type == type ? cur : NULL);
 232 }
 233
 234 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
 235 {
 236         return (opt->nd_opt_type == ND_OPT_RDNSS);
 237 }
 238
 239 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
 240                                              struct nd_opt_hdr *end)
 241 {
 242         if (!cur || !end || cur >= end)
 243                 return NULL;
 244         do {
 245                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
 246         } while(cur < end && !ndisc_is_useropt(cur));
 247         return (cur <= end && ndisc_is_useropt(cur) ? cur : NULL);
 248 }
 249
 250 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 251                                                  struct ndisc_options *ndopts)
 252 {
 253         struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 254
 255         if (!nd_opt || opt_len < 0 || !ndopts)
 256                 return NULL;
 257         memset(ndopts, 0, sizeof(*ndopts));
 258         while (opt_len) {
 259                 int l;
 260                 if (opt_len < sizeof(struct nd_opt_hdr))
 261                         return NULL;
 262                 l = nd_opt->nd_opt_len << 3;
 263                 if (opt_len < l || l == 0)
 264                         return NULL;
 265                 switch (nd_opt->nd_opt_type) {
 266                 case ND_OPT_SOURCE_LL_ADDR:
 267                 case ND_OPT_TARGET_LL_ADDR:
 268                 case ND_OPT_MTU:
 269                 case ND_OPT_REDIRECT_HDR:
 270                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 271                                 ND_PRINTK2(KERN_WARNING
 272                                            "%s(): duplicated ND6 option found: type=%d\n",
 273                                            __func__,
 274                                            nd_opt->nd_opt_type);
 275                         } else {
 276                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 277                         }
 278                         break;
 279                 case ND_OPT_PREFIX_INFO:
 280                         ndopts->nd_opts_pi_end = nd_opt;
 281                         if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 282                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 283                         break;
 284 #ifdef CONFIG_IPV6_ROUTE_INFO
 285                 case ND_OPT_ROUTE_INFO:
 286                         ndopts->nd_opts_ri_end = nd_opt;
 287                         if (!ndopts->nd_opts_ri)
 288                                 ndopts->nd_opts_ri = nd_opt;
 289                         break;
 290 #endif
 291                 default:
 292                         if (ndisc_is_useropt(nd_opt)) {
 293                                 ndopts->nd_useropts_end = nd_opt;
 294                                 if (!ndopts->nd_useropts)
 295                                         ndopts->nd_useropts = nd_opt;
 296                         } else {
 297                                 /*
 298                                  * Unknown options must be silently ignored,
 299                                  * to accommodate future extension to the
 300                                  * protocol.
 301                                  */
 302                                 ND_PRINTK2(KERN_NOTICE
 303                                            "%s(): ignored unsupported option; type=%d, len=%d\n",
 304                                            __func__,
 305                                            nd_opt->nd_opt_type, nd_opt->nd_opt_len);
 306                         }
 307                 }
 308                 opt_len -= l;
 309                 nd_opt = ((void *)nd_opt) + l;
 310         }
 311         return ndopts;
 312 }
 313
 314 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 315                                       struct net_device *dev)
 316 {
 317         u8 *lladdr = (u8 *)(p + 1);
 318         int lladdrlen = p->nd_opt_len << 3;
 319         int prepad = ndisc_addr_option_pad(dev->type);
 320         if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
 321                 return NULL;
 322         return (lladdr + prepad);
 323 }
 324
 325 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 326 {
 327         switch (dev->type) {
 328         case ARPHRD_ETHER:
 329         case ARPHRD_IEEE802:    /* Not sure. Check it later. --ANK */
 330         case ARPHRD_FDDI:
 331                 ipv6_eth_mc_map(addr, buf);
 332                 return 0;
 333         case ARPHRD_IEEE802_TR:
 334                 ipv6_tr_mc_map(addr,buf);
 335                 return 0;
 336         case ARPHRD_ARCNET:
 337                 ipv6_arcnet_mc_map(addr, buf);
 338                 return 0;
 339         case ARPHRD_INFINIBAND:
 340                 ipv6_ib_mc_map(addr, dev->broadcast, buf);
 341                 return 0;
 342         default:
 343                 if (dir) {
 344                         memcpy(buf, dev->broadcast, dev->addr_len);
 345                         return 0;
 346                 }
 347         }
 348         return -EINVAL;
 349 }
 350
 351 EXPORT_SYMBOL(ndisc_mc_map);
 352
 353 static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
 354 {
 355         const u32 *p32 = pkey;
 356         u32 addr_hash, i;
 357
 358         addr_hash = 0;
 359         for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
 360                 addr_hash ^= *p32++;
 361
 362         return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd);
 363 }
 364
 365 static int ndisc_constructor(struct neighbour *neigh)
 366 {
 367         struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
 368         struct net_device *dev = neigh->dev;
 369         struct inet6_dev *in6_dev;
 370         struct neigh_parms *parms;
 371         int is_multicast = ipv6_addr_is_multicast(addr);
 372
 373         rcu_read_lock();
 374         in6_dev = in6_dev_get(dev);
 375         if (in6_dev == NULL) {
 376                 rcu_read_unlock();
 377                 return -EINVAL;
 378         }
 379
 380         parms = in6_dev->nd_parms;
 381         __neigh_parms_put(neigh->parms);
 382         neigh->parms = neigh_parms_clone(parms);
 383         rcu_read_unlock();
 384
 385         neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 386         if (!dev->header_ops) {
 387                 neigh->nud_state = NUD_NOARP;
 388                 neigh->ops = &ndisc_direct_ops;
 389                 neigh->output = neigh->ops->queue_xmit;
 390         } else {
 391                 if (is_multicast) {
 392                         neigh->nud_state = NUD_NOARP;
 393                         ndisc_mc_map(addr, neigh->ha, dev, 1);
 394                 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 395                         neigh->nud_state = NUD_NOARP;
 396                         memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 397                         if (dev->flags&IFF_LOOPBACK)
 398                                 neigh->type = RTN_LOCAL;
 399                 } else if (dev->flags&IFF_POINTOPOINT) {
 400                         neigh->nud_state = NUD_NOARP;
 401                         memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 402                 }
 403                 if (dev->header_ops->cache)
 404                         neigh->ops = &ndisc_hh_ops;
 405                 else
 406                         neigh->ops = &ndisc_generic_ops;
 407                 if (neigh->nud_state&NUD_VALID)
 408                         neigh->output = neigh->ops->connected_output;
 409                 else
 410                         neigh->output = neigh->ops->output;
 411         }
 412         in6_dev_put(in6_dev);
 413         return 0;
 414 }
 415
 416 static int pndisc_constructor(struct pneigh_entry *n)
 417 {
 418         struct in6_addr *addr = (struct in6_addr*)&n->key;
 419         struct in6_addr maddr;
 420         struct net_device *dev = n->dev;
 421
 422         if (dev == NULL || __in6_dev_get(dev) == NULL)
 423                 return -EINVAL;
 424         addrconf_addr_solict_mult(addr, &maddr);
 425         ipv6_dev_mc_inc(dev, &maddr);
 426         return 0;
 427 }
 428
 429 static void pndisc_destructor(struct pneigh_entry *n)
 430 {
 431         struct in6_addr *addr = (struct in6_addr*)&n->key;
 432         struct in6_addr maddr;
 433         struct net_device *dev = n->dev;
 434
 435         if (dev == NULL || __in6_dev_get(dev) == NULL)
 436                 return;
 437         addrconf_addr_solict_mult(addr, &maddr);
 438         ipv6_dev_mc_dec(dev, &maddr);
 439 }
 440
 441 struct sk_buff *ndisc_build_skb(struct net_device *dev,
 442                                 const struct in6_addr *daddr,
 443                                 const struct in6_addr *saddr,
 444                                 struct icmp6hdr *icmp6h,
 445                                 const struct in6_addr *target,
 446                                 int llinfo)
 447 {
 448         struct net *net = dev_net(dev);
 449         struct sock *sk = net->ipv6.ndisc_sk;
 450         struct sk_buff *skb;
 451         struct icmp6hdr *hdr;
 452         int len;
 453         int err;
 454         u8 *opt;
 455
 456         if (!dev->addr_len)
 457                 llinfo = 0;
 458
 459         len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
 460         if (llinfo)
 461                 len += ndisc_opt_addr_space(dev);
 462
 463         skb = sock_alloc_send_skb(sk,
 464                                   (MAX_HEADER + sizeof(struct ipv6hdr) +
 465                                    len + LL_ALLOCATED_SPACE(dev)),
 466                                   1, &err);
 467         if (!skb) {
 468                 ND_PRINTK0(KERN_ERR
 469                            "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n",
 470                            __func__, err);
 471                 return NULL;
 472         }
 473
 474         skb_reserve(skb, LL_RESERVED_SPACE(dev));
 475         ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 476
 477         skb->transport_header = skb->tail;
 478         skb_put(skb, len);
 479
 480         hdr = (struct icmp6hdr *)skb_transport_header(skb);
 481         memcpy(hdr, icmp6h, sizeof(*hdr));
 482
 483         opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
 484         if (target) {
 485                 ipv6_addr_copy((struct in6_addr *)opt, target);
 486                 opt += sizeof(*target);
 487         }
 488
 489         if (llinfo)
 490                 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
 491                                        dev->addr_len, dev->type);
 492
 493         hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
 494                                            IPPROTO_ICMPV6,
 495                                            csum_partial(hdr,
 496                                                         len, 0));
 497
 498         return skb;
 499 }
 500
 501 EXPORT_SYMBOL(ndisc_build_skb);
 502
 503 void ndisc_send_skb(struct sk_buff *skb,
 504                     struct net_device *dev,
 505                     struct neighbour *neigh,
 506                     const struct in6_addr *daddr,
 507                     const struct in6_addr *saddr,
 508                     struct icmp6hdr *icmp6h)
 509 {
 510         struct flowi fl;
 511         struct dst_entry *dst;
 512         struct net *net = dev_net(dev);
 513         struct sock *sk = net->ipv6.ndisc_sk;
 514         struct inet6_dev *idev;
 515         int err;
 516         u8 type;
 517
 518         type = icmp6h->icmp6_type;
 519
 520         icmpv6_flow_init(sk, &fl, type, saddr, daddr, dev->ifindex);
 521
 522         dst = icmp6_dst_alloc(dev, neigh, daddr);
 523         if (!dst) {
 524                 kfree_skb(skb);
 525                 return;
 526         }
 527
 528         err = xfrm_lookup(net, &dst, &fl, NULL, 0);
 529         if (err < 0) {
 530                 kfree_skb(skb);
 531                 return;
 532         }
 533
 534         skb_dst_set(skb, dst);
 535
 536         idev = in6_dev_get(dst->dev);
 537         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
 538
 539         err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
 540                       dst_output);
 541         if (!err) {
 542                 ICMP6MSGOUT_INC_STATS(net, idev, type);
 543                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 544         }
 545
 546         if (likely(idev != NULL))
 547                 in6_dev_put(idev);
 548 }
 549
 550 EXPORT_SYMBOL(ndisc_send_skb);
 551
 552 /*
 553  *      Send a Neighbour Discover packet
 554  */
 555 static void __ndisc_send(struct net_device *dev,
 556                          struct neighbour *neigh,
 557                          const struct in6_addr *daddr,
 558                          const struct in6_addr *saddr,
 559                          struct icmp6hdr *icmp6h, const struct in6_addr *target,
 560                          int llinfo)
 561 {
 562         struct sk_buff *skb;
 563
 564         skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo);
 565         if (!skb)
 566                 return;
 567
 568         ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h);
 569 }
 570
 571 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
 572                           const struct in6_addr *daddr,
 573                           const struct in6_addr *solicited_addr,
 574                           int router, int solicited, int override, int inc_opt)
 575 {
 576         struct in6_addr tmpaddr;
 577         struct inet6_ifaddr *ifp;
 578         const struct in6_addr *src_addr;
 579         struct icmp6hdr icmp6h = {
 580                 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 581         };
 582
 583         /* for anycast or proxy, solicited_addr != src_addr */
 584         ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 585         if (ifp) {
 586                 src_addr = solicited_addr;
 587                 if (ifp->flags & IFA_F_OPTIMISTIC)
 588                         override = 0;
 589                 in6_ifa_put(ifp);
 590         } else {
 591                 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 592                                        inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 593                                        &tmpaddr))
 594                         return;
 595                 src_addr = &tmpaddr;
 596         }
 597
 598         icmp6h.icmp6_router = router;
 599         icmp6h.icmp6_solicited = solicited;
 600         icmp6h.icmp6_override = override;
 601
 602         inc_opt |= ifp->idev->cnf.force_tllao;
 603         __ndisc_send(dev, neigh, daddr, src_addr,
 604                      &icmp6h, solicited_addr,
 605                      inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
 606 }
 607
 608 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
 609                    const struct in6_addr *solicit,
 610                    const struct in6_addr *daddr, const struct in6_addr *saddr)
 611 {
 612         struct in6_addr addr_buf;
 613         struct icmp6hdr icmp6h = {
 614                 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 615         };
 616
 617         if (saddr == NULL) {
 618                 if (ipv6_get_lladdr(dev, &addr_buf,
 619                                    (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 620                         return;
 621                 saddr = &addr_buf;
 622         }
 623
 624         __ndisc_send(dev, neigh, daddr, saddr,
 625                      &icmp6h, solicit,
 626                      !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
 627 }
 628
 629 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 630                    const struct in6_addr *daddr)
 631 {
 632         struct icmp6hdr icmp6h = {
 633                 .icmp6_type = NDISC_ROUTER_SOLICITATION,
 634         };
 635         int send_sllao = dev->addr_len;
 636
 637 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 638         /*
 639          * According to section 2.2 of RFC 4429, we must not
 640          * send router solicitations with a sllao from
 641          * optimistic addresses, but we may send the solicitation
 642          * if we don't include the sllao.  So here we check
 643          * if our address is optimistic, and if so, we
 644          * suppress the inclusion of the sllao.
 645          */
 646         if (send_sllao) {
 647                 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 648                                                            dev, 1);
 649                 if (ifp) {
 650                         if (ifp->flags & IFA_F_OPTIMISTIC)  {
 651                                 send_sllao = 0;
 652                         }
 653                         in6_ifa_put(ifp);
 654                 } else {
 655                         send_sllao = 0;
 656                 }
 657         }
 658 #endif
 659         __ndisc_send(dev, NULL, daddr, saddr,
 660                      &icmp6h, NULL,
 661                      send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
 662 }
 663
 664
 665 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 666 {
 667         /*
 668          *      "The sender MUST return an ICMP
 669          *       destination unreachable"
 670          */
 671         dst_link_failure(skb);
 672         kfree_skb(skb);
 673 }
 674
 675 /* Called with locked neigh: either read or both */
 676
 677 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 678 {
 679         struct in6_addr *saddr = NULL;
 680         struct in6_addr mcaddr;
 681         struct net_device *dev = neigh->dev;
 682         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 683         int probes = atomic_read(&neigh->probes);
 684
 685         if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
 686                 saddr = &ipv6_hdr(skb)->saddr;
 687
 688         if ((probes -= neigh->parms->ucast_probes) < 0) {
 689                 if (!(neigh->nud_state & NUD_VALID)) {
 690                         ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n",
 691                                    __func__, target);
 692                 }
 693                 ndisc_send_ns(dev, neigh, target, target, saddr);
 694         } else if ((probes -= neigh->parms->app_probes) < 0) {
 695 #ifdef CONFIG_ARPD
 696                 neigh_app_ns(neigh);
 697 #endif
 698         } else {
 699                 addrconf_addr_solict_mult(target, &mcaddr);
 700                 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
 701         }
 702 }
 703
 704 static int pndisc_is_router(const void *pkey,
 705                             struct net_device *dev)
 706 {
 707         struct pneigh_entry *n;
 708         int ret = -1;
 709
 710         read_lock_bh(&nd_tbl.lock);
 711         n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 712         if (n)
 713                 ret = !!(n->flags & NTF_ROUTER);
 714         read_unlock_bh(&nd_tbl.lock);
 715
 716         return ret;
 717 }
 718
 719 static void ndisc_recv_ns(struct sk_buff *skb)
 720 {
 721         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 722         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 723         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 724         u8 *lladdr = NULL;
 725         u32 ndoptlen = skb->tail - (skb->transport_header +
 726                                     offsetof(struct nd_msg, opt));
 727         struct ndisc_options ndopts;
 728         struct net_device *dev = skb->dev;
 729         struct inet6_ifaddr *ifp;
 730         struct inet6_dev *idev = NULL;
 731         struct neighbour *neigh;
 732         int dad = ipv6_addr_any(saddr);
 733         int inc;
 734         int is_router = -1;
 735
 736         if (ipv6_addr_is_multicast(&msg->target)) {
 737                 ND_PRINTK2(KERN_WARNING
 738                            "ICMPv6 NS: multicast target address");
 739                 return;
 740         }
 741
 742         /*
 743          * RFC2461 7.1.1:
 744          * DAD has to be destined for solicited node multicast address.
 745          */
 746         if (dad &&
 747             !(daddr->s6_addr32[0] == htonl(0xff020000) &&
 748               daddr->s6_addr32[1] == htonl(0x00000000) &&
 749               daddr->s6_addr32[2] == htonl(0x00000001) &&
 750               daddr->s6_addr [12] == 0xff )) {
 751                 ND_PRINTK2(KERN_WARNING
 752                            "ICMPv6 NS: bad DAD packet (wrong destination)\n");
 753                 return;
 754         }
 755
 756         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 757                 ND_PRINTK2(KERN_WARNING
 758                            "ICMPv6 NS: invalid ND options\n");
 759                 return;
 760         }
 761
 762         if (ndopts.nd_opts_src_lladdr) {
 763                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 764                 if (!lladdr) {
 765                         ND_PRINTK2(KERN_WARNING
 766                                    "ICMPv6 NS: invalid link-layer address length\n");
 767                         return;
 768                 }
 769
 770                 /* RFC2461 7.1.1:
 771                  *      If the IP source address is the unspecified address,
 772                  *      there MUST NOT be source link-layer address option
 773                  *      in the message.
 774                  */
 775                 if (dad) {
 776                         ND_PRINTK2(KERN_WARNING
 777                                    "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
 778                         return;
 779                 }
 780         }
 781
 782         inc = ipv6_addr_is_multicast(daddr);
 783
 784         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 785         if (ifp) {
 786
 787                 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 788                         if (dad) {
 789                                 if (dev->type == ARPHRD_IEEE802_TR) {
 790                                         const unsigned char *sadr;
 791                                         sadr = skb_mac_header(skb);
 792                                         if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
 793                                             sadr[9] == dev->dev_addr[1] &&
 794                                             sadr[10] == dev->dev_addr[2] &&
 795                                             sadr[11] == dev->dev_addr[3] &&
 796                                             sadr[12] == dev->dev_addr[4] &&
 797                                             sadr[13] == dev->dev_addr[5]) {
 798                                                 /* looped-back to us */
 799                                                 goto out;
 800                                         }
 801                                 }
 802
 803                                 /*
 804                                  * We are colliding with another node
 805                                  * who is doing DAD
 806                                  * so fail our DAD process
 807                                  */
 808                                 addrconf_dad_failure(ifp);
 809                                 return;
 810                         } else {
 811                                 /*
 812                                  * This is not a dad solicitation.
 813                                  * If we are an optimistic node,
 814                                  * we should respond.
 815                                  * Otherwise, we should ignore it.
 816                                  */
 817                                 if (!(ifp->flags & IFA_F_OPTIMISTIC))
 818                                         goto out;
 819                         }
 820                 }
 821
 822                 idev = ifp->idev;
 823         } else {
 824                 struct net *net = dev_net(dev);
 825
 826                 idev = in6_dev_get(dev);
 827                 if (!idev) {
 828                         /* XXX: count this drop? */
 829                         return;
 830                 }
 831
 832                 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 833                     (idev->cnf.forwarding &&
 834                      (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
 835                      (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 836                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 837                             skb->pkt_type != PACKET_HOST &&
 838                             inc != 0 &&
 839                             idev->nd_parms->proxy_delay != 0) {
 840                                 /*
 841                                  * for anycast or proxy,
 842                                  * sender should delay its response
 843                                  * by a random time between 0 and
 844                                  * MAX_ANYCAST_DELAY_TIME seconds.
 845                                  * (RFC2461) -- yoshfuji
 846                                  */
 847                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 848                                 if (n)
 849                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 850                                 goto out;
 851                         }
 852                 } else
 853                         goto out;
 854         }
 855
 856         if (is_router < 0)
 857                 is_router = !!idev->cnf.forwarding;
 858
 859         if (dad) {
 860                 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
 861                               is_router, 0, (ifp != NULL), 1);
 862                 goto out;
 863         }
 864
 865         if (inc)
 866                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 867         else
 868                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 869
 870         /*
 871          *      update / create cache entry
 872          *      for the source address
 873          */
 874         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 875                                !inc || lladdr || !dev->addr_len);
 876         if (neigh)
 877                 neigh_update(neigh, lladdr, NUD_STALE,
 878                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
 879                              NEIGH_UPDATE_F_OVERRIDE);
 880         if (neigh || !dev->header_ops) {
 881                 ndisc_send_na(dev, neigh, saddr, &msg->target,
 882                               is_router,
 883                               1, (ifp != NULL && inc), inc);
 884                 if (neigh)
 885                         neigh_release(neigh);
 886         }
 887
 888 out:
 889         if (ifp)
 890                 in6_ifa_put(ifp);
 891         else
 892                 in6_dev_put(idev);
 893
 894         return;
 895 }
 896
 897 static void ndisc_recv_na(struct sk_buff *skb)
 898 {
 899         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 900         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 901         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 902         u8 *lladdr = NULL;
 903         u32 ndoptlen = skb->tail - (skb->transport_header +
 904                                     offsetof(struct nd_msg, opt));
 905         struct ndisc_options ndopts;
 906         struct net_device *dev = skb->dev;
 907         struct inet6_ifaddr *ifp;
 908         struct neighbour *neigh;
 909
 910         if (skb->len < sizeof(struct nd_msg)) {
 911                 ND_PRINTK2(KERN_WARNING
 912                            "ICMPv6 NA: packet too short\n");
 913                 return;
 914         }
 915
 916         if (ipv6_addr_is_multicast(&msg->target)) {
 917                 ND_PRINTK2(KERN_WARNING
 918                            "ICMPv6 NA: target address is multicast.\n");
 919                 return;
 920         }
 921
 922         if (ipv6_addr_is_multicast(daddr) &&
 923             msg->icmph.icmp6_solicited) {
 924                 ND_PRINTK2(KERN_WARNING
 925                            "ICMPv6 NA: solicited NA is multicasted.\n");
 926                 return;
 927         }
 928
 929         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 930                 ND_PRINTK2(KERN_WARNING
 931                            "ICMPv6 NS: invalid ND option\n");
 932                 return;
 933         }
 934         if (ndopts.nd_opts_tgt_lladdr) {
 935                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 936                 if (!lladdr) {
 937                         ND_PRINTK2(KERN_WARNING
 938                                    "ICMPv6 NA: invalid link-layer address length\n");
 939                         return;
 940                 }
 941         }
 942         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 943         if (ifp) {
 944                 if (ifp->flags & IFA_F_TENTATIVE) {
 945                         addrconf_dad_failure(ifp);
 946                         return;
 947                 }
 948                 /* What should we make now? The advertisement
 949                    is invalid, but ndisc specs say nothing
 950                    about it. It could be misconfiguration, or
 951                    an smart proxy agent tries to help us :-)
 952
 953                    We should not print the error if NA has been
 954                    received from loopback - it is just our own
 955                    unsolicited advertisement.
 956                  */
 957                 if (skb->pkt_type != PACKET_LOOPBACK)
 958                         ND_PRINTK1(KERN_WARNING
 959                            "ICMPv6 NA: someone advertises our address %pI6 on %s!\n",
 960                            &ifp->addr, ifp->idev->dev->name);
 961                 in6_ifa_put(ifp);
 962                 return;
 963         }
 964         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
 965
 966         if (neigh) {
 967                 u8 old_flags = neigh->flags;
 968                 struct net *net = dev_net(dev);
 969
 970                 if (neigh->nud_state & NUD_FAILED)
 971                         goto out;
 972
 973                 /*
 974                  * Don't update the neighbor cache entry on a proxy NA from
 975                  * ourselves because either the proxied node is off link or it
 976                  * has already sent a NA to us.
 977                  */
 978                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
 979                     net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
 980                     pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
 981                         /* XXX: idev->cnf.prixy_ndp */
 982                         goto out;
 983                 }
 984
 985                 neigh_update(neigh, lladdr,
 986                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
 987                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
 988                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
 989                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
 990                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
 991
 992                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
 993                         /*
 994                          * Change: router to host
 995                          */
 996                         struct rt6_info *rt;
 997                         rt = rt6_get_dflt_router(saddr, dev);
 998                         if (rt)
 999                                 ip6_del_rt(rt);
1000                 }
1001
1002 out:
1003                 neigh_release(neigh);
1004         }
1005 }
1006
1007 static void ndisc_recv_rs(struct sk_buff *skb)
1008 {
1009         struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1010         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1011         struct neighbour *neigh;
1012         struct inet6_dev *idev;
1013         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1014         struct ndisc_options ndopts;
1015         u8 *lladdr = NULL;
1016
1017         if (skb->len < sizeof(*rs_msg))
1018                 return;
1019
1020         idev = in6_dev_get(skb->dev);
1021         if (!idev) {
1022                 if (net_ratelimit())
1023                         ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1024                 return;
1025         }
1026
1027         /* Don't accept RS if we're not in router mode */
1028         if (!idev->cnf.forwarding)
1029                 goto out;
1030
1031         /*
1032          * Don't update NCE if src = ::;
1033          * this implies that the source node has no ip address assigned yet.
1034          */
1035         if (ipv6_addr_any(saddr))
1036                 goto out;
1037
1038         /* Parse ND options */
1039         if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1040                 if (net_ratelimit())
1041                         ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1042                 goto out;
1043         }
1044
1045         if (ndopts.nd_opts_src_lladdr) {
1046                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1047                                              skb->dev);
1048                 if (!lladdr)
1049                         goto out;
1050         }
1051
1052         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1053         if (neigh) {
1054                 neigh_update(neigh, lladdr, NUD_STALE,
1055                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1056                              NEIGH_UPDATE_F_OVERRIDE|
1057                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1058                 neigh_release(neigh);
1059         }
1060 out:
1061         in6_dev_put(idev);
1062 }
1063
1064 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1065 {
1066         struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1067         struct sk_buff *skb;
1068         struct nlmsghdr *nlh;
1069         struct nduseroptmsg *ndmsg;
1070         struct net *net = dev_net(ra->dev);
1071         int err;
1072         int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1073                                     + (opt->nd_opt_len << 3));
1074         size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1075
1076         skb = nlmsg_new(msg_size, GFP_ATOMIC);
1077         if (skb == NULL) {
1078                 err = -ENOBUFS;
1079                 goto errout;
1080         }
1081
1082         nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1083         if (nlh == NULL) {
1084                 goto nla_put_failure;
1085         }
1086
1087         ndmsg = nlmsg_data(nlh);
1088         ndmsg->nduseropt_family = AF_INET6;
1089         ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1090         ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1091         ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1092         ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1093
1094         memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1095
1096         NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1097                 &ipv6_hdr(ra)->saddr);
1098         nlmsg_end(skb, nlh);
1099
1100         rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1101         return;
1102
1103 nla_put_failure:
1104         nlmsg_free(skb);
1105         err = -EMSGSIZE;
1106 errout:
1107         rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1108 }
1109
1110 static void ndisc_router_discovery(struct sk_buff *skb)
1111 {
1112         struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1113         struct neighbour *neigh = NULL;
1114         struct inet6_dev *in6_dev;
1115         struct rt6_info *rt = NULL;
1116         int lifetime;
1117         struct ndisc_options ndopts;
1118         int optlen;
1119         unsigned int pref = 0;
1120
1121         __u8 * opt = (__u8 *)(ra_msg + 1);
1122
1123         optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
1124
1125         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1126                 ND_PRINTK2(KERN_WARNING
1127                            "ICMPv6 RA: source address is not link-local.\n");
1128                 return;
1129         }
1130         if (optlen < 0) {
1131                 ND_PRINTK2(KERN_WARNING
1132                            "ICMPv6 RA: packet too short\n");
1133                 return;
1134         }
1135
1136 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1137         if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1138                 ND_PRINTK2(KERN_WARNING
1139                            "ICMPv6 RA: from host or unauthorized router\n");
1140                 return;
1141         }
1142 #endif
1143
1144         /*
1145          *      set the RA_RECV flag in the interface
1146          */
1147
1148         in6_dev = in6_dev_get(skb->dev);
1149         if (in6_dev == NULL) {
1150                 ND_PRINTK0(KERN_ERR
1151                            "ICMPv6 RA: can't find inet6 device for %s.\n",
1152                            skb->dev->name);
1153                 return;
1154         }
1155
1156         if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1157                 in6_dev_put(in6_dev);
1158                 ND_PRINTK2(KERN_WARNING
1159                            "ICMP6 RA: invalid ND options\n");
1160                 return;
1161         }
1162
1163         /* skip route and link configuration on routers */
1164         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra)
1165                 goto skip_linkparms;
1166
1167 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1168         /* skip link-specific parameters from interior routers */
1169         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1170                 goto skip_linkparms;
1171 #endif
1172
1173         if (in6_dev->if_flags & IF_RS_SENT) {
1174                 /*
1175                  *      flag that an RA was received after an RS was sent
1176                  *      out on this interface.
1177                  */
1178                 in6_dev->if_flags |= IF_RA_RCVD;
1179         }
1180
1181         /*
1182          * Remember the managed/otherconf flags from most recently
1183          * received RA message (RFC 2462) -- yoshfuji
1184          */
1185         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1186                                 IF_RA_OTHERCONF)) |
1187                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1188                                         IF_RA_MANAGED : 0) |
1189                                 (ra_msg->icmph.icmp6_addrconf_other ?
1190                                         IF_RA_OTHERCONF : 0);
1191
1192         if (!in6_dev->cnf.accept_ra_defrtr)
1193                 goto skip_defrtr;
1194
1195         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1196
1197 #ifdef CONFIG_IPV6_ROUTER_PREF
1198         pref = ra_msg->icmph.icmp6_router_pref;
1199         /* 10b is handled as if it were 00b (medium) */
1200         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1201             !in6_dev->cnf.accept_ra_rtr_pref)
1202                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1203 #endif
1204
1205         rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1206
1207         if (rt)
1208                 neigh = rt->rt6i_nexthop;
1209
1210         if (rt && lifetime == 0) {
1211                 neigh_clone(neigh);
1212                 ip6_del_rt(rt);
1213                 rt = NULL;
1214         }
1215
1216         if (rt == NULL && lifetime) {
1217                 ND_PRINTK3(KERN_DEBUG
1218                            "ICMPv6 RA: adding default router.\n");
1219
1220                 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1221                 if (rt == NULL) {
1222                         ND_PRINTK0(KERN_ERR
1223                                    "ICMPv6 RA: %s() failed to add default route.\n",
1224                                    __func__);
1225                         in6_dev_put(in6_dev);
1226                         return;
1227                 }
1228
1229                 neigh = rt->rt6i_nexthop;
1230                 if (neigh == NULL) {
1231                         ND_PRINTK0(KERN_ERR
1232                                    "ICMPv6 RA: %s() got default router without neighbour.\n",
1233                                    __func__);
1234                         dst_release(&rt->u.dst);
1235                         in6_dev_put(in6_dev);
1236                         return;
1237                 }
1238                 neigh->flags |= NTF_ROUTER;
1239         } else if (rt) {
1240                 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1241         }
1242
1243         if (rt)
1244                 rt->rt6i_expires = jiffies + (HZ * lifetime);
1245
1246         if (ra_msg->icmph.icmp6_hop_limit) {
1247                 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1248                 if (rt)
1249                         rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
1250         }
1251
1252 skip_defrtr:
1253
1254         /*
1255          *      Update Reachable Time and Retrans Timer
1256          */
1257
1258         if (in6_dev->nd_parms) {
1259                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1260
1261                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1262                         rtime = (rtime*HZ)/1000;
1263                         if (rtime < HZ/10)
1264                                 rtime = HZ/10;
1265                         in6_dev->nd_parms->retrans_time = rtime;
1266                         in6_dev->tstamp = jiffies;
1267                         inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1268                 }
1269
1270                 rtime = ntohl(ra_msg->reachable_time);
1271                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1272                         rtime = (rtime*HZ)/1000;
1273
1274                         if (rtime < HZ/10)
1275                                 rtime = HZ/10;
1276
1277                         if (rtime != in6_dev->nd_parms->base_reachable_time) {
1278                                 in6_dev->nd_parms->base_reachable_time = rtime;
1279                                 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1280                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1281                                 in6_dev->tstamp = jiffies;
1282                                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1283                         }
1284                 }
1285         }
1286
1287 skip_linkparms:
1288
1289         /*
1290          *      Process options.
1291          */
1292
1293         if (!neigh)
1294                 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1295                                        skb->dev, 1);
1296         if (neigh) {
1297                 u8 *lladdr = NULL;
1298                 if (ndopts.nd_opts_src_lladdr) {
1299                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1300                                                      skb->dev);
1301                         if (!lladdr) {
1302                                 ND_PRINTK2(KERN_WARNING
1303                                            "ICMPv6 RA: invalid link-layer address length\n");
1304                                 goto out;
1305                         }
1306                 }
1307                 neigh_update(neigh, lladdr, NUD_STALE,
1308                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1309                              NEIGH_UPDATE_F_OVERRIDE|
1310                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1311                              NEIGH_UPDATE_F_ISROUTER);
1312         }
1313
1314         /* skip route and link configuration on routers */
1315         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra)
1316                 goto out;
1317
1318 #ifdef CONFIG_IPV6_ROUTE_INFO
1319         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1320                 struct nd_opt_hdr *p;
1321                 for (p = ndopts.nd_opts_ri;
1322                      p;
1323                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1324                         struct route_info *ri = (struct route_info *)p;
1325 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1326                         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1327                             ri->prefix_len == 0)
1328                                 continue;
1329 #endif
1330                         if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1331                                 continue;
1332                         rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1333                                       &ipv6_hdr(skb)->saddr);
1334                 }
1335         }
1336 #endif
1337
1338 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1339         /* skip link-specific ndopts from interior routers */
1340         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1341                 goto out;
1342 #endif
1343
1344         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1345                 struct nd_opt_hdr *p;
1346                 for (p = ndopts.nd_opts_pi;
1347                      p;
1348                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1349                         addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1350                 }
1351         }
1352
1353         if (ndopts.nd_opts_mtu) {
1354                 __be32 n;
1355                 u32 mtu;
1356
1357                 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1358                 mtu = ntohl(n);
1359
1360                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1361                         ND_PRINTK2(KERN_WARNING
1362                                    "ICMPv6 RA: invalid mtu: %d\n",
1363                                    mtu);
1364                 } else if (in6_dev->cnf.mtu6 != mtu) {
1365                         in6_dev->cnf.mtu6 = mtu;
1366
1367                         if (rt)
1368                                 rt->u.dst.metrics[RTAX_MTU-1] = mtu;
1369
1370                         rt6_mtu_change(skb->dev, mtu);
1371                 }
1372         }
1373
1374         if (ndopts.nd_useropts) {
1375                 struct nd_opt_hdr *p;
1376                 for (p = ndopts.nd_useropts;
1377                      p;
1378                      p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1379                         ndisc_ra_useropt(skb, p);
1380                 }
1381         }
1382
1383         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1384                 ND_PRINTK2(KERN_WARNING
1385                            "ICMPv6 RA: invalid RA options");
1386         }
1387 out:
1388         if (rt)
1389                 dst_release(&rt->u.dst);
1390         else if (neigh)
1391                 neigh_release(neigh);
1392         in6_dev_put(in6_dev);
1393 }
1394
1395 static void ndisc_redirect_rcv(struct sk_buff *skb)
1396 {
1397         struct inet6_dev *in6_dev;
1398         struct icmp6hdr *icmph;
1399         struct in6_addr *dest;
1400         struct in6_addr *target;        /* new first hop to destination */
1401         struct neighbour *neigh;
1402         int on_link = 0;
1403         struct ndisc_options ndopts;
1404         int optlen;
1405         u8 *lladdr = NULL;
1406
1407 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1408         switch (skb->ndisc_nodetype) {
1409         case NDISC_NODETYPE_HOST:
1410         case NDISC_NODETYPE_NODEFAULT:
1411                 ND_PRINTK2(KERN_WARNING
1412                            "ICMPv6 Redirect: from host or unauthorized router\n");
1413                 return;
1414         }
1415 #endif
1416
1417         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1418                 ND_PRINTK2(KERN_WARNING
1419                            "ICMPv6 Redirect: source address is not link-local.\n");
1420                 return;
1421         }
1422
1423         optlen = skb->tail - skb->transport_header;
1424         optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1425
1426         if (optlen < 0) {
1427                 ND_PRINTK2(KERN_WARNING
1428                            "ICMPv6 Redirect: packet too short\n");
1429                 return;
1430         }
1431
1432         icmph = icmp6_hdr(skb);
1433         target = (struct in6_addr *) (icmph + 1);
1434         dest = target + 1;
1435
1436         if (ipv6_addr_is_multicast(dest)) {
1437                 ND_PRINTK2(KERN_WARNING
1438                            "ICMPv6 Redirect: destination address is multicast.\n");
1439                 return;
1440         }
1441
1442         if (ipv6_addr_equal(dest, target)) {
1443                 on_link = 1;
1444         } else if (ipv6_addr_type(target) !=
1445                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1446                 ND_PRINTK2(KERN_WARNING
1447                            "ICMPv6 Redirect: target address is not link-local unicast.\n");
1448                 return;
1449         }
1450
1451         in6_dev = in6_dev_get(skb->dev);
1452         if (!in6_dev)
1453                 return;
1454         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1455                 in6_dev_put(in6_dev);
1456                 return;
1457         }
1458
1459         /* RFC2461 8.1:
1460          *      The IP source address of the Redirect MUST be the same as the current
1461          *      first-hop router for the specified ICMP Destination Address.
1462          */
1463
1464         if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1465                 ND_PRINTK2(KERN_WARNING
1466                            "ICMPv6 Redirect: invalid ND options\n");
1467                 in6_dev_put(in6_dev);
1468                 return;
1469         }
1470         if (ndopts.nd_opts_tgt_lladdr) {
1471                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1472                                              skb->dev);
1473                 if (!lladdr) {
1474                         ND_PRINTK2(KERN_WARNING
1475                                    "ICMPv6 Redirect: invalid link-layer address length\n");
1476                         in6_dev_put(in6_dev);
1477                         return;
1478                 }
1479         }
1480
1481         neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1482         if (neigh) {
1483                 rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
1484                              &ipv6_hdr(skb)->saddr, neigh, lladdr,
1485                              on_link);
1486                 neigh_release(neigh);
1487         }
1488         in6_dev_put(in6_dev);
1489 }
1490
1491 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1492                          const struct in6_addr *target)
1493 {
1494         struct net_device *dev = skb->dev;
1495         struct net *net = dev_net(dev);
1496         struct sock *sk = net->ipv6.ndisc_sk;
1497         int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1498         struct sk_buff *buff;
1499         struct icmp6hdr *icmph;
1500         struct in6_addr saddr_buf;
1501         struct in6_addr *addrp;
1502         struct rt6_info *rt;
1503         struct dst_entry *dst;
1504         struct inet6_dev *idev;
1505         struct flowi fl;
1506         u8 *opt;
1507         int rd_len;
1508         int err;
1509         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1510
1511         if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1512                 ND_PRINTK2(KERN_WARNING
1513                            "ICMPv6 Redirect: no link-local address on %s\n",
1514                            dev->name);
1515                 return;
1516         }
1517
1518         if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1519             ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1520                 ND_PRINTK2(KERN_WARNING
1521                         "ICMPv6 Redirect: target address is not link-local unicast.\n");
1522                 return;
1523         }
1524
1525         icmpv6_flow_init(sk, &fl, NDISC_REDIRECT,
1526                          &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1527
1528         dst = ip6_route_output(net, NULL, &fl);
1529         if (dst == NULL)
1530                 return;
1531
1532         err = xfrm_lookup(net, &dst, &fl, NULL, 0);
1533         if (err)
1534                 return;
1535
1536         rt = (struct rt6_info *) dst;
1537
1538         if (rt->rt6i_flags & RTF_GATEWAY) {
1539                 ND_PRINTK2(KERN_WARNING
1540                            "ICMPv6 Redirect: destination is not a neighbour.\n");
1541                 goto release;
1542         }
1543         if (!xrlim_allow(dst, 1*HZ))
1544                 goto release;
1545
1546         if (dev->addr_len) {
1547                 read_lock_bh(&neigh->lock);
1548                 if (neigh->nud_state & NUD_VALID) {
1549                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1550                         read_unlock_bh(&neigh->lock);
1551                         ha = ha_buf;
1552                         len += ndisc_opt_addr_space(dev);
1553                 } else
1554                         read_unlock_bh(&neigh->lock);
1555         }
1556
1557         rd_len = min_t(unsigned int,
1558                      IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1559         rd_len &= ~0x7;
1560         len += rd_len;
1561
1562         buff = sock_alloc_send_skb(sk,
1563                                    (MAX_HEADER + sizeof(struct ipv6hdr) +
1564                                     len + LL_ALLOCATED_SPACE(dev)),
1565                                    1, &err);
1566         if (buff == NULL) {
1567                 ND_PRINTK0(KERN_ERR
1568                            "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n",
1569                            __func__, err);
1570                 goto release;
1571         }
1572
1573         skb_reserve(buff, LL_RESERVED_SPACE(dev));
1574         ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
1575                    IPPROTO_ICMPV6, len);
1576
1577         skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1578         skb_put(buff, len);
1579         icmph = icmp6_hdr(buff);
1580
1581         memset(icmph, 0, sizeof(struct icmp6hdr));
1582         icmph->icmp6_type = NDISC_REDIRECT;
1583
1584         /*
1585          *      copy target and destination addresses
1586          */
1587
1588         addrp = (struct in6_addr *)(icmph + 1);
1589         ipv6_addr_copy(addrp, target);
1590         addrp++;
1591         ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr);
1592
1593         opt = (u8*) (addrp + 1);
1594
1595         /*
1596          *      include target_address option
1597          */
1598
1599         if (ha)
1600                 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1601                                              dev->addr_len, dev->type);
1602
1603         /*
1604          *      build redirect option and copy skb over to the new packet.
1605          */
1606
1607         memset(opt, 0, 8);
1608         *(opt++) = ND_OPT_REDIRECT_HDR;
1609         *(opt++) = (rd_len >> 3);
1610         opt += 6;
1611
1612         memcpy(opt, ipv6_hdr(skb), rd_len - 8);
1613
1614         icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
1615                                              len, IPPROTO_ICMPV6,
1616                                              csum_partial(icmph, len, 0));
1617
1618         skb_dst_set(buff, dst);
1619         idev = in6_dev_get(dst->dev);
1620         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1621         err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
1622                       dst_output);
1623         if (!err) {
1624                 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT);
1625                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1626         }
1627
1628         if (likely(idev != NULL))
1629                 in6_dev_put(idev);
1630         return;
1631
1632 release:
1633         dst_release(dst);
1634 }
1635
1636 static void pndisc_redo(struct sk_buff *skb)
1637 {
1638         ndisc_recv_ns(skb);
1639         kfree_skb(skb);
1640 }
1641
1642 int ndisc_rcv(struct sk_buff *skb)
1643 {
1644         struct nd_msg *msg;
1645
1646         if (!pskb_may_pull(skb, skb->len))
1647                 return 0;
1648
1649         msg = (struct nd_msg *)skb_transport_header(skb);
1650
1651         __skb_push(skb, skb->data - skb_transport_header(skb));
1652
1653         if (ipv6_hdr(skb)->hop_limit != 255) {
1654                 ND_PRINTK2(KERN_WARNING
1655                            "ICMPv6 NDISC: invalid hop-limit: %d\n",
1656                            ipv6_hdr(skb)->hop_limit);
1657                 return 0;
1658         }
1659
1660         if (msg->icmph.icmp6_code != 0) {
1661                 ND_PRINTK2(KERN_WARNING
1662                            "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1663                            msg->icmph.icmp6_code);
1664                 return 0;
1665         }
1666
1667         memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1668
1669         switch (msg->icmph.icmp6_type) {
1670         case NDISC_NEIGHBOUR_SOLICITATION:
1671                 ndisc_recv_ns(skb);
1672                 break;
1673
1674         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1675                 ndisc_recv_na(skb);
1676                 break;
1677
1678         case NDISC_ROUTER_SOLICITATION:
1679                 ndisc_recv_rs(skb);
1680                 break;
1681
1682         case NDISC_ROUTER_ADVERTISEMENT:
1683                 ndisc_router_discovery(skb);
1684                 break;
1685
1686         case NDISC_REDIRECT:
1687                 ndisc_redirect_rcv(skb);
1688                 break;
1689         }
1690
1691         return 0;
1692 }
1693
1694 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1695 {
1696         struct net_device *dev = ptr;
1697         struct net *net = dev_net(dev);
1698
1699         switch (event) {
1700         case NETDEV_CHANGEADDR:
1701                 neigh_changeaddr(&nd_tbl, dev);
1702                 fib6_run_gc(~0UL, net);
1703                 break;
1704         case NETDEV_DOWN:
1705                 neigh_ifdown(&nd_tbl, dev);
1706                 fib6_run_gc(~0UL, net);
1707                 break;
1708         default:
1709                 break;
1710         }
1711
1712         return NOTIFY_DONE;
1713 }
1714
1715 static struct notifier_block ndisc_netdev_notifier = {
1716         .notifier_call = ndisc_netdev_event,
1717 };
1718
1719 #ifdef CONFIG_SYSCTL
1720 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1721                                          const char *func, const char *dev_name)
1722 {
1723         static char warncomm[TASK_COMM_LEN];
1724         static int warned;
1725         if (strcmp(warncomm, current->comm) && warned < 5) {
1726                 strcpy(warncomm, current->comm);
1727                 printk(KERN_WARNING
1728                         "process `%s' is using deprecated sysctl (%s) "
1729                         "net.ipv6.neigh.%s.%s; "
1730                         "Use net.ipv6.neigh.%s.%s_ms "
1731                         "instead.\n",
1732                         warncomm, func,
1733                         dev_name, ctl->procname,
1734                         dev_name, ctl->procname);
1735                 warned++;
1736         }
1737 }
1738
1739 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1740 {
1741         struct net_device *dev = ctl->extra1;
1742         struct inet6_dev *idev;
1743         int ret;
1744
1745         if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1746             (strcmp(ctl->procname, "base_reachable_time") == 0))
1747                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1748
1749         if (strcmp(ctl->procname, "retrans_time") == 0)
1750                 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1751
1752         else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1753                 ret = proc_dointvec_jiffies(ctl, write,
1754                                             buffer, lenp, ppos);
1755
1756         else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1757                  (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1758                 ret = proc_dointvec_ms_jiffies(ctl, write,
1759                                                buffer, lenp, ppos);
1760         else
1761                 ret = -1;
1762
1763         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1764                 if (ctl->data == &idev->nd_parms->base_reachable_time)
1765                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1766                 idev->tstamp = jiffies;
1767                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1768                 in6_dev_put(idev);
1769         }
1770         return ret;
1771 }
1772
1773
1774 #endif
1775
1776 static int __net_init ndisc_net_init(struct net *net)
1777 {
1778         struct ipv6_pinfo *np;
1779         struct sock *sk;
1780         int err;
1781
1782         err = inet_ctl_sock_create(&sk, PF_INET6,
1783                                    SOCK_RAW, IPPROTO_ICMPV6, net);
1784         if (err < 0) {
1785                 ND_PRINTK0(KERN_ERR
1786                            "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1787                            err);
1788                 return err;
1789         }
1790
1791         net->ipv6.ndisc_sk = sk;
1792
1793         np = inet6_sk(sk);
1794         np->hop_limit = 255;
1795         /* Do not loopback ndisc messages */
1796         np->mc_loop = 0;
1797
1798         return 0;
1799 }
1800
1801 static void __net_exit ndisc_net_exit(struct net *net)
1802 {
1803         inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1804 }
1805
1806 static struct pernet_operations ndisc_net_ops = {
1807         .init = ndisc_net_init,
1808         .exit = ndisc_net_exit,
1809 };
1810
1811 int __init ndisc_init(void)
1812 {
1813         int err;
1814
1815         err = register_pernet_subsys(&ndisc_net_ops);
1816         if (err)
1817                 return err;
1818         /*
1819          * Initialize the neighbour table
1820          */
1821         neigh_table_init(&nd_tbl);
1822
1823 #ifdef CONFIG_SYSCTL
1824         err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6",
1825                                     &ndisc_ifinfo_sysctl_change);
1826         if (err)
1827                 goto out_unregister_pernet;
1828 #endif
1829         err = register_netdevice_notifier(&ndisc_netdev_notifier);
1830         if (err)
1831                 goto out_unregister_sysctl;
1832 out:
1833         return err;
1834
1835 out_unregister_sysctl:
1836 #ifdef CONFIG_SYSCTL
1837         neigh_sysctl_unregister(&nd_tbl.parms);
1838 out_unregister_pernet:
1839 #endif
1840         unregister_pernet_subsys(&ndisc_net_ops);
1841         goto out;
1842 }
1843
1844 void ndisc_cleanup(void)
1845 {
1846         unregister_netdevice_notifier(&ndisc_netdev_notifier);
1847 #ifdef CONFIG_SYSCTL
1848         neigh_sysctl_unregister(&nd_tbl.parms);
1849 #endif
1850         neigh_table_clear(&nd_tbl);
1851         unregister_pernet_subsys(&ndisc_net_ops);
1852 }