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   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 #ifdef CONFIG_SYSCTL
  63 #include <linux/sysctl.h>
  64 #endif
  65
  66 #include <linux/if_addr.h>
  67 #include <linux/if_arp.h>
  68 #include <linux/ipv6.h>
  69 #include <linux/icmpv6.h>
  70 #include <linux/jhash.h>
  71
  72 #include <net/sock.h>
  73 #include <net/snmp.h>
  74
  75 #include <net/ipv6.h>
  76 #include <net/protocol.h>
  77 #include <net/ndisc.h>
  78 #include <net/ip6_route.h>
  79 #include <net/addrconf.h>
  80 #include <net/icmp.h>
  81
  82 #include <net/netlink.h>
  83 #include <linux/rtnetlink.h>
  84
  85 #include <net/flow.h>
  86 #include <net/ip6_checksum.h>
  87 #include <net/inet_common.h>
  88 #include <linux/proc_fs.h>
  89
  90 #include <linux/netfilter.h>
  91 #include <linux/netfilter_ipv6.h>
  92
  93 static u32 ndisc_hash(const void *pkey, const struct net_device *dev);
  94 static int ndisc_constructor(struct neighbour *neigh);
  95 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
  96 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
  97 static int pndisc_constructor(struct pneigh_entry *n);
  98 static void pndisc_destructor(struct pneigh_entry *n);
  99 static void pndisc_redo(struct sk_buff *skb);
 100
 101 static struct neigh_ops ndisc_generic_ops = {
 102         .family =               AF_INET6,
 103         .solicit =              ndisc_solicit,
 104         .error_report =         ndisc_error_report,
 105         .output =               neigh_resolve_output,
 106         .connected_output =     neigh_connected_output,
 107         .hh_output =            dev_queue_xmit,
 108         .queue_xmit =           dev_queue_xmit,
 109 };
 110
 111 static struct neigh_ops ndisc_hh_ops = {
 112         .family =               AF_INET6,
 113         .solicit =              ndisc_solicit,
 114         .error_report =         ndisc_error_report,
 115         .output =               neigh_resolve_output,
 116         .connected_output =     neigh_resolve_output,
 117         .hh_output =            dev_queue_xmit,
 118         .queue_xmit =           dev_queue_xmit,
 119 };
 120
 121
 122 static struct neigh_ops ndisc_direct_ops = {
 123         .family =               AF_INET6,
 124         .output =               dev_queue_xmit,
 125         .connected_output =     dev_queue_xmit,
 126         .hh_output =            dev_queue_xmit,
 127         .queue_xmit =           dev_queue_xmit,
 128 };
 129
 130 struct neigh_table nd_tbl = {
 131         .family =       AF_INET6,
 132         .entry_size =   sizeof(struct neighbour) + sizeof(struct in6_addr),
 133         .key_len =      sizeof(struct in6_addr),
 134         .hash =         ndisc_hash,
 135         .constructor =  ndisc_constructor,
 136         .pconstructor = pndisc_constructor,
 137         .pdestructor =  pndisc_destructor,
 138         .proxy_redo =   pndisc_redo,
 139         .id =           "ndisc_cache",
 140         .parms = {
 141                 .tbl =                  &nd_tbl,
 142                 .base_reachable_time =  30 * HZ,
 143                 .retrans_time =  1 * HZ,
 144                 .gc_staletime = 60 * HZ,
 145                 .reachable_time =               30 * HZ,
 146                 .delay_probe_time =      5 * HZ,
 147                 .queue_len =             3,
 148                 .ucast_probes =  3,
 149                 .mcast_probes =  3,
 150                 .anycast_delay =         1 * HZ,
 151                 .proxy_delay =          (8 * HZ) / 10,
 152                 .proxy_qlen =           64,
 153         },
 154         .gc_interval =    30 * HZ,
 155         .gc_thresh1 =    128,
 156         .gc_thresh2 =    512,
 157         .gc_thresh3 =   1024,
 158 };
 159
 160 /* ND options */
 161 struct ndisc_options {
 162         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 163 #ifdef CONFIG_IPV6_ROUTE_INFO
 164         struct nd_opt_hdr *nd_opts_ri;
 165         struct nd_opt_hdr *nd_opts_ri_end;
 166 #endif
 167         struct nd_opt_hdr *nd_useropts;
 168         struct nd_opt_hdr *nd_useropts_end;
 169 };
 170
 171 #define nd_opts_src_lladdr      nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
 172 #define nd_opts_tgt_lladdr      nd_opt_array[ND_OPT_TARGET_LL_ADDR]
 173 #define nd_opts_pi              nd_opt_array[ND_OPT_PREFIX_INFO]
 174 #define nd_opts_pi_end          nd_opt_array[__ND_OPT_PREFIX_INFO_END]
 175 #define nd_opts_rh              nd_opt_array[ND_OPT_REDIRECT_HDR]
 176 #define nd_opts_mtu             nd_opt_array[ND_OPT_MTU]
 177
 178 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 179
 180 /*
 181  * Return the padding between the option length and the start of the
 182  * link addr.  Currently only IP-over-InfiniBand needs this, although
 183  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 184  * also need a pad of 2.
 185  */
 186 static int ndisc_addr_option_pad(unsigned short type)
 187 {
 188         switch (type) {
 189         case ARPHRD_INFINIBAND: return 2;
 190         default:                return 0;
 191         }
 192 }
 193
 194 static inline int ndisc_opt_addr_space(struct net_device *dev)
 195 {
 196         return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
 197 }
 198
 199 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
 200                                   unsigned short addr_type)
 201 {
 202         int space = NDISC_OPT_SPACE(data_len);
 203         int pad   = ndisc_addr_option_pad(addr_type);
 204
 205         opt[0] = type;
 206         opt[1] = space>>3;
 207
 208         memset(opt + 2, 0, pad);
 209         opt   += pad;
 210         space -= pad;
 211
 212         memcpy(opt+2, data, data_len);
 213         data_len += 2;
 214         opt += data_len;
 215         if ((space -= data_len) > 0)
 216                 memset(opt, 0, space);
 217         return opt + space;
 218 }
 219
 220 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 221                                             struct nd_opt_hdr *end)
 222 {
 223         int type;
 224         if (!cur || !end || cur >= end)
 225                 return NULL;
 226         type = cur->nd_opt_type;
 227         do {
 228                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
 229         } while(cur < end && cur->nd_opt_type != type);
 230         return (cur <= end && cur->nd_opt_type == type ? cur : NULL);
 231 }
 232
 233 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
 234 {
 235         return (opt->nd_opt_type == ND_OPT_RDNSS);
 236 }
 237
 238 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
 239                                              struct nd_opt_hdr *end)
 240 {
 241         if (!cur || !end || cur >= end)
 242                 return NULL;
 243         do {
 244                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
 245         } while(cur < end && !ndisc_is_useropt(cur));
 246         return (cur <= end && ndisc_is_useropt(cur) ? cur : NULL);
 247 }
 248
 249 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 250                                                  struct ndisc_options *ndopts)
 251 {
 252         struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 253
 254         if (!nd_opt || opt_len < 0 || !ndopts)
 255                 return NULL;
 256         memset(ndopts, 0, sizeof(*ndopts));
 257         while (opt_len) {
 258                 int l;
 259                 if (opt_len < sizeof(struct nd_opt_hdr))
 260                         return NULL;
 261                 l = nd_opt->nd_opt_len << 3;
 262                 if (opt_len < l || l == 0)
 263                         return NULL;
 264                 switch (nd_opt->nd_opt_type) {
 265                 case ND_OPT_SOURCE_LL_ADDR:
 266                 case ND_OPT_TARGET_LL_ADDR:
 267                 case ND_OPT_MTU:
 268                 case ND_OPT_REDIRECT_HDR:
 269                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 270                                 ND_PRINTK2(KERN_WARNING
 271                                            "%s(): duplicated ND6 option found: type=%d\n",
 272                                            __func__,
 273                                            nd_opt->nd_opt_type);
 274                         } else {
 275                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 276                         }
 277                         break;
 278                 case ND_OPT_PREFIX_INFO:
 279                         ndopts->nd_opts_pi_end = nd_opt;
 280                         if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 281                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 282                         break;
 283 #ifdef CONFIG_IPV6_ROUTE_INFO
 284                 case ND_OPT_ROUTE_INFO:
 285                         ndopts->nd_opts_ri_end = nd_opt;
 286                         if (!ndopts->nd_opts_ri)
 287                                 ndopts->nd_opts_ri = nd_opt;
 288                         break;
 289 #endif
 290                 default:
 291                         if (ndisc_is_useropt(nd_opt)) {
 292                                 ndopts->nd_useropts_end = nd_opt;
 293                                 if (!ndopts->nd_useropts)
 294                                         ndopts->nd_useropts = nd_opt;
 295                         } else {
 296                                 /*
 297                                  * Unknown options must be silently ignored,
 298                                  * to accommodate future extension to the
 299                                  * protocol.
 300                                  */
 301                                 ND_PRINTK2(KERN_NOTICE
 302                                            "%s(): ignored unsupported option; type=%d, len=%d\n",
 303                                            __func__,
 304                                            nd_opt->nd_opt_type, nd_opt->nd_opt_len);
 305                         }
 306                 }
 307                 opt_len -= l;
 308                 nd_opt = ((void *)nd_opt) + l;
 309         }
 310         return ndopts;
 311 }
 312
 313 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 314                                       struct net_device *dev)
 315 {
 316         u8 *lladdr = (u8 *)(p + 1);
 317         int lladdrlen = p->nd_opt_len << 3;
 318         int prepad = ndisc_addr_option_pad(dev->type);
 319         if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
 320                 return NULL;
 321         return (lladdr + prepad);
 322 }
 323
 324 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 325 {
 326         switch (dev->type) {
 327         case ARPHRD_ETHER:
 328         case ARPHRD_IEEE802:    /* Not sure. Check it later. --ANK */
 329         case ARPHRD_FDDI:
 330                 ipv6_eth_mc_map(addr, buf);
 331                 return 0;
 332         case ARPHRD_IEEE802_TR:
 333                 ipv6_tr_mc_map(addr,buf);
 334                 return 0;
 335         case ARPHRD_ARCNET:
 336                 ipv6_arcnet_mc_map(addr, buf);
 337                 return 0;
 338         case ARPHRD_INFINIBAND:
 339                 ipv6_ib_mc_map(addr, dev->broadcast, buf);
 340                 return 0;
 341         default:
 342                 if (dir) {
 343                         memcpy(buf, dev->broadcast, dev->addr_len);
 344                         return 0;
 345                 }
 346         }
 347         return -EINVAL;
 348 }
 349
 350 EXPORT_SYMBOL(ndisc_mc_map);
 351
 352 static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
 353 {
 354         const u32 *p32 = pkey;
 355         u32 addr_hash, i;
 356
 357         addr_hash = 0;
 358         for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
 359                 addr_hash ^= *p32++;
 360
 361         return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd);
 362 }
 363
 364 static int ndisc_constructor(struct neighbour *neigh)
 365 {
 366         struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
 367         struct net_device *dev = neigh->dev;
 368         struct inet6_dev *in6_dev;
 369         struct neigh_parms *parms;
 370         int is_multicast = ipv6_addr_is_multicast(addr);
 371
 372         rcu_read_lock();
 373         in6_dev = in6_dev_get(dev);
 374         if (in6_dev == NULL) {
 375                 rcu_read_unlock();
 376                 return -EINVAL;
 377         }
 378
 379         parms = in6_dev->nd_parms;
 380         __neigh_parms_put(neigh->parms);
 381         neigh->parms = neigh_parms_clone(parms);
 382         rcu_read_unlock();
 383
 384         neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 385         if (!dev->header_ops) {
 386                 neigh->nud_state = NUD_NOARP;
 387                 neigh->ops = &ndisc_direct_ops;
 388                 neigh->output = neigh->ops->queue_xmit;
 389         } else {
 390                 if (is_multicast) {
 391                         neigh->nud_state = NUD_NOARP;
 392                         ndisc_mc_map(addr, neigh->ha, dev, 1);
 393                 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 394                         neigh->nud_state = NUD_NOARP;
 395                         memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 396                         if (dev->flags&IFF_LOOPBACK)
 397                                 neigh->type = RTN_LOCAL;
 398                 } else if (dev->flags&IFF_POINTOPOINT) {
 399                         neigh->nud_state = NUD_NOARP;
 400                         memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 401                 }
 402                 if (dev->header_ops->cache)
 403                         neigh->ops = &ndisc_hh_ops;
 404                 else
 405                         neigh->ops = &ndisc_generic_ops;
 406                 if (neigh->nud_state&NUD_VALID)
 407                         neigh->output = neigh->ops->connected_output;
 408                 else
 409                         neigh->output = neigh->ops->output;
 410         }
 411         in6_dev_put(in6_dev);
 412         return 0;
 413 }
 414
 415 static int pndisc_constructor(struct pneigh_entry *n)
 416 {
 417         struct in6_addr *addr = (struct in6_addr*)&n->key;
 418         struct in6_addr maddr;
 419         struct net_device *dev = n->dev;
 420
 421         if (dev == NULL || __in6_dev_get(dev) == NULL)
 422                 return -EINVAL;
 423         addrconf_addr_solict_mult(addr, &maddr);
 424         ipv6_dev_mc_inc(dev, &maddr);
 425         return 0;
 426 }
 427
 428 static void pndisc_destructor(struct pneigh_entry *n)
 429 {
 430         struct in6_addr *addr = (struct in6_addr*)&n->key;
 431         struct in6_addr maddr;
 432         struct net_device *dev = n->dev;
 433
 434         if (dev == NULL || __in6_dev_get(dev) == NULL)
 435                 return;
 436         addrconf_addr_solict_mult(addr, &maddr);
 437         ipv6_dev_mc_dec(dev, &maddr);
 438 }
 439
 440 struct sk_buff *ndisc_build_skb(struct net_device *dev,
 441                                 const struct in6_addr *daddr,
 442                                 const struct in6_addr *saddr,
 443                                 struct icmp6hdr *icmp6h,
 444                                 const struct in6_addr *target,
 445                                 int llinfo)
 446 {
 447         struct net *net = dev_net(dev);
 448         struct sock *sk = net->ipv6.ndisc_sk;
 449         struct sk_buff *skb;
 450         struct icmp6hdr *hdr;
 451         int len;
 452         int err;
 453         u8 *opt;
 454
 455         if (!dev->addr_len)
 456                 llinfo = 0;
 457
 458         len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
 459         if (llinfo)
 460                 len += ndisc_opt_addr_space(dev);
 461
 462         skb = sock_alloc_send_skb(sk,
 463                                   (MAX_HEADER + sizeof(struct ipv6hdr) +
 464                                    len + LL_ALLOCATED_SPACE(dev)),
 465                                   1, &err);
 466         if (!skb) {
 467                 ND_PRINTK0(KERN_ERR
 468                            "ICMPv6 ND: %s() failed to allocate an skb.\n",
 469                            __func__);
 470                 return NULL;
 471         }
 472
 473         skb_reserve(skb, LL_RESERVED_SPACE(dev));
 474         ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 475
 476         skb->transport_header = skb->tail;
 477         skb_put(skb, len);
 478
 479         hdr = (struct icmp6hdr *)skb_transport_header(skb);
 480         memcpy(hdr, icmp6h, sizeof(*hdr));
 481
 482         opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
 483         if (target) {
 484                 ipv6_addr_copy((struct in6_addr *)opt, target);
 485                 opt += sizeof(*target);
 486         }
 487
 488         if (llinfo)
 489                 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
 490                                        dev->addr_len, dev->type);
 491
 492         hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
 493                                            IPPROTO_ICMPV6,
 494                                            csum_partial(hdr,
 495                                                         len, 0));
 496
 497         return skb;
 498 }
 499
 500 EXPORT_SYMBOL(ndisc_build_skb);
 501
 502 void ndisc_send_skb(struct sk_buff *skb,
 503                     struct net_device *dev,
 504                     struct neighbour *neigh,
 505                     const struct in6_addr *daddr,
 506                     const struct in6_addr *saddr,
 507                     struct icmp6hdr *icmp6h)
 508 {
 509         struct flowi fl;
 510         struct dst_entry *dst;
 511         struct net *net = dev_net(dev);
 512         struct sock *sk = net->ipv6.ndisc_sk;
 513         struct inet6_dev *idev;
 514         int err;
 515         u8 type;
 516
 517         type = icmp6h->icmp6_type;
 518
 519         icmpv6_flow_init(sk, &fl, type, saddr, daddr, dev->ifindex);
 520
 521         dst = icmp6_dst_alloc(dev, neigh, daddr);
 522         if (!dst) {
 523                 kfree_skb(skb);
 524                 return;
 525         }
 526
 527         err = xfrm_lookup(net, &dst, &fl, NULL, 0);
 528         if (err < 0) {
 529                 kfree_skb(skb);
 530                 return;
 531         }
 532
 533         skb->dst = dst;
 534
 535         idev = in6_dev_get(dst->dev);
 536         IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
 537
 538         err = NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
 539                       dst_output);
 540         if (!err) {
 541                 ICMP6MSGOUT_INC_STATS(net, idev, type);
 542                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 543         }
 544
 545         if (likely(idev != NULL))
 546                 in6_dev_put(idev);
 547 }
 548
 549 EXPORT_SYMBOL(ndisc_send_skb);
 550
 551 /*
 552  *      Send a Neighbour Discover packet
 553  */
 554 static void __ndisc_send(struct net_device *dev,
 555                          struct neighbour *neigh,
 556                          const struct in6_addr *daddr,
 557                          const struct in6_addr *saddr,
 558                          struct icmp6hdr *icmp6h, const struct in6_addr *target,
 559                          int llinfo)
 560 {
 561         struct sk_buff *skb;
 562
 563         skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo);
 564         if (!skb)
 565                 return;
 566
 567         ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h);
 568 }
 569
 570 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
 571                           const struct in6_addr *daddr,
 572                           const struct in6_addr *solicited_addr,
 573                           int router, int solicited, int override, int inc_opt)
 574 {
 575         struct in6_addr tmpaddr;
 576         struct inet6_ifaddr *ifp;
 577         const struct in6_addr *src_addr;
 578         struct icmp6hdr icmp6h = {
 579                 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 580         };
 581
 582         /* for anycast or proxy, solicited_addr != src_addr */
 583         ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 584         if (ifp) {
 585                 src_addr = solicited_addr;
 586                 if (ifp->flags & IFA_F_OPTIMISTIC)
 587                         override = 0;
 588                 in6_ifa_put(ifp);
 589         } else {
 590                 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 591                                        inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 592                                        &tmpaddr))
 593                         return;
 594                 src_addr = &tmpaddr;
 595         }
 596
 597         icmp6h.icmp6_router = router;
 598         icmp6h.icmp6_solicited = solicited;
 599         icmp6h.icmp6_override = override;
 600
 601         __ndisc_send(dev, neigh, daddr, src_addr,
 602                      &icmp6h, solicited_addr,
 603                      inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
 604 }
 605
 606 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
 607                    const struct in6_addr *solicit,
 608                    const struct in6_addr *daddr, const struct in6_addr *saddr)
 609 {
 610         struct in6_addr addr_buf;
 611         struct icmp6hdr icmp6h = {
 612                 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 613         };
 614
 615         if (saddr == NULL) {
 616                 if (ipv6_get_lladdr(dev, &addr_buf,
 617                                    (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 618                         return;
 619                 saddr = &addr_buf;
 620         }
 621
 622         __ndisc_send(dev, neigh, daddr, saddr,
 623                      &icmp6h, solicit,
 624                      !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
 625 }
 626
 627 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 628                    const struct in6_addr *daddr)
 629 {
 630         struct icmp6hdr icmp6h = {
 631                 .icmp6_type = NDISC_ROUTER_SOLICITATION,
 632         };
 633         int send_sllao = dev->addr_len;
 634
 635 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 636         /*
 637          * According to section 2.2 of RFC 4429, we must not
 638          * send router solicitations with a sllao from
 639          * optimistic addresses, but we may send the solicitation
 640          * if we don't include the sllao.  So here we check
 641          * if our address is optimistic, and if so, we
 642          * suppress the inclusion of the sllao.
 643          */
 644         if (send_sllao) {
 645                 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 646                                                            dev, 1);
 647                 if (ifp) {
 648                         if (ifp->flags & IFA_F_OPTIMISTIC)  {
 649                                 send_sllao = 0;
 650                         }
 651                         in6_ifa_put(ifp);
 652                 } else {
 653                         send_sllao = 0;
 654                 }
 655         }
 656 #endif
 657         __ndisc_send(dev, NULL, daddr, saddr,
 658                      &icmp6h, NULL,
 659                      send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
 660 }
 661
 662
 663 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 664 {
 665         /*
 666          *      "The sender MUST return an ICMP
 667          *       destination unreachable"
 668          */
 669         dst_link_failure(skb);
 670         kfree_skb(skb);
 671 }
 672
 673 /* Called with locked neigh: either read or both */
 674
 675 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 676 {
 677         struct in6_addr *saddr = NULL;
 678         struct in6_addr mcaddr;
 679         struct net_device *dev = neigh->dev;
 680         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 681         int probes = atomic_read(&neigh->probes);
 682
 683         if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
 684                 saddr = &ipv6_hdr(skb)->saddr;
 685
 686         if ((probes -= neigh->parms->ucast_probes) < 0) {
 687                 if (!(neigh->nud_state & NUD_VALID)) {
 688                         ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n",
 689                                    __func__, target);
 690                 }
 691                 ndisc_send_ns(dev, neigh, target, target, saddr);
 692         } else if ((probes -= neigh->parms->app_probes) < 0) {
 693 #ifdef CONFIG_ARPD
 694                 neigh_app_ns(neigh);
 695 #endif
 696         } else {
 697                 addrconf_addr_solict_mult(target, &mcaddr);
 698                 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
 699         }
 700 }
 701
 702 static int pndisc_is_router(const void *pkey,
 703                             struct net_device *dev)
 704 {
 705         struct pneigh_entry *n;
 706         int ret = -1;
 707
 708         read_lock_bh(&nd_tbl.lock);
 709         n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 710         if (n)
 711                 ret = !!(n->flags & NTF_ROUTER);
 712         read_unlock_bh(&nd_tbl.lock);
 713
 714         return ret;
 715 }
 716
 717 static void ndisc_recv_ns(struct sk_buff *skb)
 718 {
 719         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 720         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 721         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 722         u8 *lladdr = NULL;
 723         u32 ndoptlen = skb->tail - (skb->transport_header +
 724                                     offsetof(struct nd_msg, opt));
 725         struct ndisc_options ndopts;
 726         struct net_device *dev = skb->dev;
 727         struct inet6_ifaddr *ifp;
 728         struct inet6_dev *idev = NULL;
 729         struct neighbour *neigh;
 730         int dad = ipv6_addr_any(saddr);
 731         int inc;
 732         int is_router = -1;
 733
 734         if (ipv6_addr_is_multicast(&msg->target)) {
 735                 ND_PRINTK2(KERN_WARNING
 736                            "ICMPv6 NS: multicast target address");
 737                 return;
 738         }
 739
 740         /*
 741          * RFC2461 7.1.1:
 742          * DAD has to be destined for solicited node multicast address.
 743          */
 744         if (dad &&
 745             !(daddr->s6_addr32[0] == htonl(0xff020000) &&
 746               daddr->s6_addr32[1] == htonl(0x00000000) &&
 747               daddr->s6_addr32[2] == htonl(0x00000001) &&
 748               daddr->s6_addr [12] == 0xff )) {
 749                 ND_PRINTK2(KERN_WARNING
 750                            "ICMPv6 NS: bad DAD packet (wrong destination)\n");
 751                 return;
 752         }
 753
 754         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 755                 ND_PRINTK2(KERN_WARNING
 756                            "ICMPv6 NS: invalid ND options\n");
 757                 return;
 758         }
 759
 760         if (ndopts.nd_opts_src_lladdr) {
 761                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 762                 if (!lladdr) {
 763                         ND_PRINTK2(KERN_WARNING
 764                                    "ICMPv6 NS: invalid link-layer address length\n");
 765                         return;
 766                 }
 767
 768                 /* RFC2461 7.1.1:
 769                  *      If the IP source address is the unspecified address,
 770                  *      there MUST NOT be source link-layer address option
 771                  *      in the message.
 772                  */
 773                 if (dad) {
 774                         ND_PRINTK2(KERN_WARNING
 775                                    "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
 776                         return;
 777                 }
 778         }
 779
 780         inc = ipv6_addr_is_multicast(daddr);
 781
 782         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 783         if (ifp) {
 784
 785                 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 786                         if (dad) {
 787                                 if (dev->type == ARPHRD_IEEE802_TR) {
 788                                         const unsigned char *sadr;
 789                                         sadr = skb_mac_header(skb);
 790                                         if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
 791                                             sadr[9] == dev->dev_addr[1] &&
 792                                             sadr[10] == dev->dev_addr[2] &&
 793                                             sadr[11] == dev->dev_addr[3] &&
 794                                             sadr[12] == dev->dev_addr[4] &&
 795                                             sadr[13] == dev->dev_addr[5]) {
 796                                                 /* looped-back to us */
 797                                                 goto out;
 798                                         }
 799                                 }
 800
 801                                 /*
 802                                  * We are colliding with another node
 803                                  * who is doing DAD
 804                                  * so fail our DAD process
 805                                  */
 806                                 addrconf_dad_failure(ifp);
 807                                 return;
 808                         } else {
 809                                 /*
 810                                  * This is not a dad solicitation.
 811                                  * If we are an optimistic node,
 812                                  * we should respond.
 813                                  * Otherwise, we should ignore it.
 814                                  */
 815                                 if (!(ifp->flags & IFA_F_OPTIMISTIC))
 816                                         goto out;
 817                         }
 818                 }
 819
 820                 idev = ifp->idev;
 821         } else {
 822                 struct net *net = dev_net(dev);
 823
 824                 idev = in6_dev_get(dev);
 825                 if (!idev) {
 826                         /* XXX: count this drop? */
 827                         return;
 828                 }
 829
 830                 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 831                     (idev->cnf.forwarding &&
 832                      (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
 833                      (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 834                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 835                             skb->pkt_type != PACKET_HOST &&
 836                             inc != 0 &&
 837                             idev->nd_parms->proxy_delay != 0) {
 838                                 /*
 839                                  * for anycast or proxy,
 840                                  * sender should delay its response
 841                                  * by a random time between 0 and
 842                                  * MAX_ANYCAST_DELAY_TIME seconds.
 843                                  * (RFC2461) -- yoshfuji
 844                                  */
 845                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 846                                 if (n)
 847                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 848                                 goto out;
 849                         }
 850                 } else
 851                         goto out;
 852         }
 853
 854         if (is_router < 0)
 855                 is_router = !!idev->cnf.forwarding;
 856
 857         if (dad) {
 858                 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
 859                               is_router, 0, (ifp != NULL), 1);
 860                 goto out;
 861         }
 862
 863         if (inc)
 864                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 865         else
 866                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 867
 868         /*
 869          *      update / create cache entry
 870          *      for the source address
 871          */
 872         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 873                                !inc || lladdr || !dev->addr_len);
 874         if (neigh)
 875                 neigh_update(neigh, lladdr, NUD_STALE,
 876                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
 877                              NEIGH_UPDATE_F_OVERRIDE);
 878         if (neigh || !dev->header_ops) {
 879                 ndisc_send_na(dev, neigh, saddr, &msg->target,
 880                               is_router,
 881                               1, (ifp != NULL && inc), inc);
 882                 if (neigh)
 883                         neigh_release(neigh);
 884         }
 885
 886 out:
 887         if (ifp)
 888                 in6_ifa_put(ifp);
 889         else
 890                 in6_dev_put(idev);
 891
 892         return;
 893 }
 894
 895 static void ndisc_recv_na(struct sk_buff *skb)
 896 {
 897         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 898         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 899         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 900         u8 *lladdr = NULL;
 901         u32 ndoptlen = skb->tail - (skb->transport_header +
 902                                     offsetof(struct nd_msg, opt));
 903         struct ndisc_options ndopts;
 904         struct net_device *dev = skb->dev;
 905         struct inet6_ifaddr *ifp;
 906         struct neighbour *neigh;
 907
 908         if (skb->len < sizeof(struct nd_msg)) {
 909                 ND_PRINTK2(KERN_WARNING
 910                            "ICMPv6 NA: packet too short\n");
 911                 return;
 912         }
 913
 914         if (ipv6_addr_is_multicast(&msg->target)) {
 915                 ND_PRINTK2(KERN_WARNING
 916                            "ICMPv6 NA: target address is multicast.\n");
 917                 return;
 918         }
 919
 920         if (ipv6_addr_is_multicast(daddr) &&
 921             msg->icmph.icmp6_solicited) {
 922                 ND_PRINTK2(KERN_WARNING
 923                            "ICMPv6 NA: solicited NA is multicasted.\n");
 924                 return;
 925         }
 926
 927         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 928                 ND_PRINTK2(KERN_WARNING
 929                            "ICMPv6 NS: invalid ND option\n");
 930                 return;
 931         }
 932         if (ndopts.nd_opts_tgt_lladdr) {
 933                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 934                 if (!lladdr) {
 935                         ND_PRINTK2(KERN_WARNING
 936                                    "ICMPv6 NA: invalid link-layer address length\n");
 937                         return;
 938                 }
 939         }
 940         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 941         if (ifp) {
 942                 if (ifp->flags & IFA_F_TENTATIVE) {
 943                         addrconf_dad_failure(ifp);
 944                         return;
 945                 }
 946                 /* What should we make now? The advertisement
 947                    is invalid, but ndisc specs say nothing
 948                    about it. It could be misconfiguration, or
 949                    an smart proxy agent tries to help us :-)
 950                  */
 951                 ND_PRINTK1(KERN_WARNING
 952                            "ICMPv6 NA: someone advertises our address on %s!\n",
 953                            ifp->idev->dev->name);
 954                 in6_ifa_put(ifp);
 955                 return;
 956         }
 957         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
 958
 959         if (neigh) {
 960                 u8 old_flags = neigh->flags;
 961                 struct net *net = dev_net(dev);
 962
 963                 if (neigh->nud_state & NUD_FAILED)
 964                         goto out;
 965
 966                 /*
 967                  * Don't update the neighbor cache entry on a proxy NA from
 968                  * ourselves because either the proxied node is off link or it
 969                  * has already sent a NA to us.
 970                  */
 971                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
 972                     net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
 973                     pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
 974                         /* XXX: idev->cnf.prixy_ndp */
 975                         goto out;
 976                 }
 977
 978                 neigh_update(neigh, lladdr,
 979                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
 980                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
 981                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
 982                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
 983                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
 984
 985                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
 986                         /*
 987                          * Change: router to host
 988                          */
 989                         struct rt6_info *rt;
 990                         rt = rt6_get_dflt_router(saddr, dev);
 991                         if (rt)
 992                                 ip6_del_rt(rt);
 993                 }
 994
 995 out:
 996                 neigh_release(neigh);
 997         }
 998 }
 999
1000 static void ndisc_recv_rs(struct sk_buff *skb)
1001 {
1002         struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1003         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1004         struct neighbour *neigh;
1005         struct inet6_dev *idev;
1006         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1007         struct ndisc_options ndopts;
1008         u8 *lladdr = NULL;
1009
1010         if (skb->len < sizeof(*rs_msg))
1011                 return;
1012
1013         idev = in6_dev_get(skb->dev);
1014         if (!idev) {
1015                 if (net_ratelimit())
1016                         ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1017                 return;
1018         }
1019
1020         /* Don't accept RS if we're not in router mode */
1021         if (!idev->cnf.forwarding)
1022                 goto out;
1023
1024         /*
1025          * Don't update NCE if src = ::;
1026          * this implies that the source node has no ip address assigned yet.
1027          */
1028         if (ipv6_addr_any(saddr))
1029                 goto out;
1030
1031         /* Parse ND options */
1032         if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1033                 if (net_ratelimit())
1034                         ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1035                 goto out;
1036         }
1037
1038         if (ndopts.nd_opts_src_lladdr) {
1039                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1040                                              skb->dev);
1041                 if (!lladdr)
1042                         goto out;
1043         }
1044
1045         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1046         if (neigh) {
1047                 neigh_update(neigh, lladdr, NUD_STALE,
1048                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1049                              NEIGH_UPDATE_F_OVERRIDE|
1050                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1051                 neigh_release(neigh);
1052         }
1053 out:
1054         in6_dev_put(idev);
1055 }
1056
1057 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1058 {
1059         struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1060         struct sk_buff *skb;
1061         struct nlmsghdr *nlh;
1062         struct nduseroptmsg *ndmsg;
1063         struct net *net = dev_net(ra->dev);
1064         int err;
1065         int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1066                                     + (opt->nd_opt_len << 3));
1067         size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1068
1069         skb = nlmsg_new(msg_size, GFP_ATOMIC);
1070         if (skb == NULL) {
1071                 err = -ENOBUFS;
1072                 goto errout;
1073         }
1074
1075         nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1076         if (nlh == NULL) {
1077                 goto nla_put_failure;
1078         }
1079
1080         ndmsg = nlmsg_data(nlh);
1081         ndmsg->nduseropt_family = AF_INET6;
1082         ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1083         ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1084         ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1085         ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1086
1087         memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1088
1089         NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1090                 &ipv6_hdr(ra)->saddr);
1091         nlmsg_end(skb, nlh);
1092
1093         err = rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL,
1094                           GFP_ATOMIC);
1095         if (err < 0)
1096                 goto errout;
1097
1098         return;
1099
1100 nla_put_failure:
1101         nlmsg_free(skb);
1102         err = -EMSGSIZE;
1103 errout:
1104         rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1105 }
1106
1107 static void ndisc_router_discovery(struct sk_buff *skb)
1108 {
1109         struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1110         struct neighbour *neigh = NULL;
1111         struct inet6_dev *in6_dev;
1112         struct rt6_info *rt = NULL;
1113         int lifetime;
1114         struct ndisc_options ndopts;
1115         int optlen;
1116         unsigned int pref = 0;
1117
1118         __u8 * opt = (__u8 *)(ra_msg + 1);
1119
1120         optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
1121
1122         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1123                 ND_PRINTK2(KERN_WARNING
1124                            "ICMPv6 RA: source address is not link-local.\n");
1125                 return;
1126         }
1127         if (optlen < 0) {
1128                 ND_PRINTK2(KERN_WARNING
1129                            "ICMPv6 RA: packet too short\n");
1130                 return;
1131         }
1132
1133 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1134         if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1135                 ND_PRINTK2(KERN_WARNING
1136                            "ICMPv6 RA: from host or unauthorized router\n");
1137                 return;
1138         }
1139 #endif
1140
1141         /*
1142          *      set the RA_RECV flag in the interface
1143          */
1144
1145         in6_dev = in6_dev_get(skb->dev);
1146         if (in6_dev == NULL) {
1147                 ND_PRINTK0(KERN_ERR
1148                            "ICMPv6 RA: can't find inet6 device for %s.\n",
1149                            skb->dev->name);
1150                 return;
1151         }
1152         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) {
1153                 in6_dev_put(in6_dev);
1154                 return;
1155         }
1156
1157         if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1158                 in6_dev_put(in6_dev);
1159                 ND_PRINTK2(KERN_WARNING
1160                            "ICMP6 RA: invalid ND options\n");
1161                 return;
1162         }
1163
1164 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1165         /* skip link-specific parameters from interior routers */
1166         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1167                 goto skip_linkparms;
1168 #endif
1169
1170         if (in6_dev->if_flags & IF_RS_SENT) {
1171                 /*
1172                  *      flag that an RA was received after an RS was sent
1173                  *      out on this interface.
1174                  */
1175                 in6_dev->if_flags |= IF_RA_RCVD;
1176         }
1177
1178         /*
1179          * Remember the managed/otherconf flags from most recently
1180          * received RA message (RFC 2462) -- yoshfuji
1181          */
1182         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1183                                 IF_RA_OTHERCONF)) |
1184                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1185                                         IF_RA_MANAGED : 0) |
1186                                 (ra_msg->icmph.icmp6_addrconf_other ?
1187                                         IF_RA_OTHERCONF : 0);
1188
1189         if (!in6_dev->cnf.accept_ra_defrtr)
1190                 goto skip_defrtr;
1191
1192         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1193
1194 #ifdef CONFIG_IPV6_ROUTER_PREF
1195         pref = ra_msg->icmph.icmp6_router_pref;
1196         /* 10b is handled as if it were 00b (medium) */
1197         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1198             !in6_dev->cnf.accept_ra_rtr_pref)
1199                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1200 #endif
1201
1202         rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1203
1204         if (rt)
1205                 neigh = rt->rt6i_nexthop;
1206
1207         if (rt && lifetime == 0) {
1208                 neigh_clone(neigh);
1209                 ip6_del_rt(rt);
1210                 rt = NULL;
1211         }
1212
1213         if (rt == NULL && lifetime) {
1214                 ND_PRINTK3(KERN_DEBUG
1215                            "ICMPv6 RA: adding default router.\n");
1216
1217                 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1218                 if (rt == NULL) {
1219                         ND_PRINTK0(KERN_ERR
1220                                    "ICMPv6 RA: %s() failed to add default route.\n",
1221                                    __func__);
1222                         in6_dev_put(in6_dev);
1223                         return;
1224                 }
1225
1226                 neigh = rt->rt6i_nexthop;
1227                 if (neigh == NULL) {
1228                         ND_PRINTK0(KERN_ERR
1229                                    "ICMPv6 RA: %s() got default router without neighbour.\n",
1230                                    __func__);
1231                         dst_release(&rt->u.dst);
1232                         in6_dev_put(in6_dev);
1233                         return;
1234                 }
1235                 neigh->flags |= NTF_ROUTER;
1236         } else if (rt) {
1237                 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1238         }
1239
1240         if (rt)
1241                 rt->rt6i_expires = jiffies + (HZ * lifetime);
1242
1243         if (ra_msg->icmph.icmp6_hop_limit) {
1244                 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1245                 if (rt)
1246                         rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
1247         }
1248
1249 skip_defrtr:
1250
1251         /*
1252          *      Update Reachable Time and Retrans Timer
1253          */
1254
1255         if (in6_dev->nd_parms) {
1256                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1257
1258                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1259                         rtime = (rtime*HZ)/1000;
1260                         if (rtime < HZ/10)
1261                                 rtime = HZ/10;
1262                         in6_dev->nd_parms->retrans_time = rtime;
1263                         in6_dev->tstamp = jiffies;
1264                         inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1265                 }
1266
1267                 rtime = ntohl(ra_msg->reachable_time);
1268                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1269                         rtime = (rtime*HZ)/1000;
1270
1271                         if (rtime < HZ/10)
1272                                 rtime = HZ/10;
1273
1274                         if (rtime != in6_dev->nd_parms->base_reachable_time) {
1275                                 in6_dev->nd_parms->base_reachable_time = rtime;
1276                                 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1277                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1278                                 in6_dev->tstamp = jiffies;
1279                                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1280                         }
1281                 }
1282         }
1283
1284 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1285 skip_linkparms:
1286 #endif
1287
1288         /*
1289          *      Process options.
1290          */
1291
1292         if (!neigh)
1293                 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1294                                        skb->dev, 1);
1295         if (neigh) {
1296                 u8 *lladdr = NULL;
1297                 if (ndopts.nd_opts_src_lladdr) {
1298                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1299                                                      skb->dev);
1300                         if (!lladdr) {
1301                                 ND_PRINTK2(KERN_WARNING
1302                                            "ICMPv6 RA: invalid link-layer address length\n");
1303                                 goto out;
1304                         }
1305                 }
1306                 neigh_update(neigh, lladdr, NUD_STALE,
1307                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1308                              NEIGH_UPDATE_F_OVERRIDE|
1309                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1310                              NEIGH_UPDATE_F_ISROUTER);
1311         }
1312
1313 #ifdef CONFIG_IPV6_ROUTE_INFO
1314         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1315                 struct nd_opt_hdr *p;
1316                 for (p = ndopts.nd_opts_ri;
1317                      p;
1318                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1319                         struct route_info *ri = (struct route_info *)p;
1320 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1321                         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1322                             ri->prefix_len == 0)
1323                                 continue;
1324 #endif
1325                         if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1326                                 continue;
1327                         rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1328                                       &ipv6_hdr(skb)->saddr);
1329                 }
1330         }
1331 #endif
1332
1333 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1334         /* skip link-specific ndopts from interior routers */
1335         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1336                 goto out;
1337 #endif
1338
1339         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1340                 struct nd_opt_hdr *p;
1341                 for (p = ndopts.nd_opts_pi;
1342                      p;
1343                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1344                         addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1345                 }
1346         }
1347
1348         if (ndopts.nd_opts_mtu) {
1349                 __be32 n;
1350                 u32 mtu;
1351
1352                 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1353                 mtu = ntohl(n);
1354
1355                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1356                         ND_PRINTK2(KERN_WARNING
1357                                    "ICMPv6 RA: invalid mtu: %d\n",
1358                                    mtu);
1359                 } else if (in6_dev->cnf.mtu6 != mtu) {
1360                         in6_dev->cnf.mtu6 = mtu;
1361
1362                         if (rt)
1363                                 rt->u.dst.metrics[RTAX_MTU-1] = mtu;
1364
1365                         rt6_mtu_change(skb->dev, mtu);
1366                 }
1367         }
1368
1369         if (ndopts.nd_useropts) {
1370                 struct nd_opt_hdr *p;
1371                 for (p = ndopts.nd_useropts;
1372                      p;
1373                      p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1374                         ndisc_ra_useropt(skb, p);
1375                 }
1376         }
1377
1378         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1379                 ND_PRINTK2(KERN_WARNING
1380                            "ICMPv6 RA: invalid RA options");
1381         }
1382 out:
1383         if (rt)
1384                 dst_release(&rt->u.dst);
1385         else if (neigh)
1386                 neigh_release(neigh);
1387         in6_dev_put(in6_dev);
1388 }
1389
1390 static void ndisc_redirect_rcv(struct sk_buff *skb)
1391 {
1392         struct inet6_dev *in6_dev;
1393         struct icmp6hdr *icmph;
1394         struct in6_addr *dest;
1395         struct in6_addr *target;        /* new first hop to destination */
1396         struct neighbour *neigh;
1397         int on_link = 0;
1398         struct ndisc_options ndopts;
1399         int optlen;
1400         u8 *lladdr = NULL;
1401
1402 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1403         switch (skb->ndisc_nodetype) {
1404         case NDISC_NODETYPE_HOST:
1405         case NDISC_NODETYPE_NODEFAULT:
1406                 ND_PRINTK2(KERN_WARNING
1407                            "ICMPv6 Redirect: from host or unauthorized router\n");
1408                 return;
1409         }
1410 #endif
1411
1412         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1413                 ND_PRINTK2(KERN_WARNING
1414                            "ICMPv6 Redirect: source address is not link-local.\n");
1415                 return;
1416         }
1417
1418         optlen = skb->tail - skb->transport_header;
1419         optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1420
1421         if (optlen < 0) {
1422                 ND_PRINTK2(KERN_WARNING
1423                            "ICMPv6 Redirect: packet too short\n");
1424                 return;
1425         }
1426
1427         icmph = icmp6_hdr(skb);
1428         target = (struct in6_addr *) (icmph + 1);
1429         dest = target + 1;
1430
1431         if (ipv6_addr_is_multicast(dest)) {
1432                 ND_PRINTK2(KERN_WARNING
1433                            "ICMPv6 Redirect: destination address is multicast.\n");
1434                 return;
1435         }
1436
1437         if (ipv6_addr_equal(dest, target)) {
1438                 on_link = 1;
1439         } else if (ipv6_addr_type(target) !=
1440                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1441                 ND_PRINTK2(KERN_WARNING
1442                            "ICMPv6 Redirect: target address is not link-local unicast.\n");
1443                 return;
1444         }
1445
1446         in6_dev = in6_dev_get(skb->dev);
1447         if (!in6_dev)
1448                 return;
1449         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1450                 in6_dev_put(in6_dev);
1451                 return;
1452         }
1453
1454         /* RFC2461 8.1:
1455          *      The IP source address of the Redirect MUST be the same as the current
1456          *      first-hop router for the specified ICMP Destination Address.
1457          */
1458
1459         if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1460                 ND_PRINTK2(KERN_WARNING
1461                            "ICMPv6 Redirect: invalid ND options\n");
1462                 in6_dev_put(in6_dev);
1463                 return;
1464         }
1465         if (ndopts.nd_opts_tgt_lladdr) {
1466                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1467                                              skb->dev);
1468                 if (!lladdr) {
1469                         ND_PRINTK2(KERN_WARNING
1470                                    "ICMPv6 Redirect: invalid link-layer address length\n");
1471                         in6_dev_put(in6_dev);
1472                         return;
1473                 }
1474         }
1475
1476         neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1477         if (neigh) {
1478                 rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
1479                              &ipv6_hdr(skb)->saddr, neigh, lladdr,
1480                              on_link);
1481                 neigh_release(neigh);
1482         }
1483         in6_dev_put(in6_dev);
1484 }
1485
1486 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1487                          const struct in6_addr *target)
1488 {
1489         struct net_device *dev = skb->dev;
1490         struct net *net = dev_net(dev);
1491         struct sock *sk = net->ipv6.ndisc_sk;
1492         int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1493         struct sk_buff *buff;
1494         struct icmp6hdr *icmph;
1495         struct in6_addr saddr_buf;
1496         struct in6_addr *addrp;
1497         struct rt6_info *rt;
1498         struct dst_entry *dst;
1499         struct inet6_dev *idev;
1500         struct flowi fl;
1501         u8 *opt;
1502         int rd_len;
1503         int err;
1504         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1505
1506         if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1507                 ND_PRINTK2(KERN_WARNING
1508                            "ICMPv6 Redirect: no link-local address on %s\n",
1509                            dev->name);
1510                 return;
1511         }
1512
1513         if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1514             ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1515                 ND_PRINTK2(KERN_WARNING
1516                         "ICMPv6 Redirect: target address is not link-local unicast.\n");
1517                 return;
1518         }
1519
1520         icmpv6_flow_init(sk, &fl, NDISC_REDIRECT,
1521                          &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1522
1523         dst = ip6_route_output(net, NULL, &fl);
1524         if (dst == NULL)
1525                 return;
1526
1527         err = xfrm_lookup(net, &dst, &fl, NULL, 0);
1528         if (err)
1529                 return;
1530
1531         rt = (struct rt6_info *) dst;
1532
1533         if (rt->rt6i_flags & RTF_GATEWAY) {
1534                 ND_PRINTK2(KERN_WARNING
1535                            "ICMPv6 Redirect: destination is not a neighbour.\n");
1536                 dst_release(dst);
1537                 return;
1538         }
1539         if (!xrlim_allow(dst, 1*HZ)) {
1540                 dst_release(dst);
1541                 return;
1542         }
1543
1544         if (dev->addr_len) {
1545                 read_lock_bh(&neigh->lock);
1546                 if (neigh->nud_state & NUD_VALID) {
1547                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1548                         read_unlock_bh(&neigh->lock);
1549                         ha = ha_buf;
1550                         len += ndisc_opt_addr_space(dev);
1551                 } else
1552                         read_unlock_bh(&neigh->lock);
1553         }
1554
1555         rd_len = min_t(unsigned int,
1556                      IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1557         rd_len &= ~0x7;
1558         len += rd_len;
1559
1560         buff = sock_alloc_send_skb(sk,
1561                                    (MAX_HEADER + sizeof(struct ipv6hdr) +
1562                                     len + LL_ALLOCATED_SPACE(dev)),
1563                                    1, &err);
1564         if (buff == NULL) {
1565                 ND_PRINTK0(KERN_ERR
1566                            "ICMPv6 Redirect: %s() failed to allocate an skb.\n",
1567                            __func__);
1568                 dst_release(dst);
1569                 return;
1570         }
1571
1572         skb_reserve(buff, LL_RESERVED_SPACE(dev));
1573         ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
1574                    IPPROTO_ICMPV6, len);
1575
1576         skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1577         skb_put(buff, len);
1578         icmph = icmp6_hdr(buff);
1579
1580         memset(icmph, 0, sizeof(struct icmp6hdr));
1581         icmph->icmp6_type = NDISC_REDIRECT;
1582
1583         /*
1584          *      copy target and destination addresses
1585          */
1586
1587         addrp = (struct in6_addr *)(icmph + 1);
1588         ipv6_addr_copy(addrp, target);
1589         addrp++;
1590         ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr);
1591
1592         opt = (u8*) (addrp + 1);
1593
1594         /*
1595          *      include target_address option
1596          */
1597
1598         if (ha)
1599                 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1600                                              dev->addr_len, dev->type);
1601
1602         /*
1603          *      build redirect option and copy skb over to the new packet.
1604          */
1605
1606         memset(opt, 0, 8);
1607         *(opt++) = ND_OPT_REDIRECT_HDR;
1608         *(opt++) = (rd_len >> 3);
1609         opt += 6;
1610
1611         memcpy(opt, ipv6_hdr(skb), rd_len - 8);
1612
1613         icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
1614                                              len, IPPROTO_ICMPV6,
1615                                              csum_partial(icmph, len, 0));
1616
1617         buff->dst = dst;
1618         idev = in6_dev_get(dst->dev);
1619         IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
1620         err = NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
1621                       dst_output);
1622         if (!err) {
1623                 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT);
1624                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1625         }
1626
1627         if (likely(idev != NULL))
1628                 in6_dev_put(idev);
1629 }
1630
1631 static void pndisc_redo(struct sk_buff *skb)
1632 {
1633         ndisc_recv_ns(skb);
1634         kfree_skb(skb);
1635 }
1636
1637 int ndisc_rcv(struct sk_buff *skb)
1638 {
1639         struct nd_msg *msg;
1640
1641         if (!pskb_may_pull(skb, skb->len))
1642                 return 0;
1643
1644         msg = (struct nd_msg *)skb_transport_header(skb);
1645
1646         __skb_push(skb, skb->data - skb_transport_header(skb));
1647
1648         if (ipv6_hdr(skb)->hop_limit != 255) {
1649                 ND_PRINTK2(KERN_WARNING
1650                            "ICMPv6 NDISC: invalid hop-limit: %d\n",
1651                            ipv6_hdr(skb)->hop_limit);
1652                 return 0;
1653         }
1654
1655         if (msg->icmph.icmp6_code != 0) {
1656                 ND_PRINTK2(KERN_WARNING
1657                            "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1658                            msg->icmph.icmp6_code);
1659                 return 0;
1660         }
1661
1662         memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1663
1664         switch (msg->icmph.icmp6_type) {
1665         case NDISC_NEIGHBOUR_SOLICITATION:
1666                 ndisc_recv_ns(skb);
1667                 break;
1668
1669         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1670                 ndisc_recv_na(skb);
1671                 break;
1672
1673         case NDISC_ROUTER_SOLICITATION:
1674                 ndisc_recv_rs(skb);
1675                 break;
1676
1677         case NDISC_ROUTER_ADVERTISEMENT:
1678                 ndisc_router_discovery(skb);
1679                 break;
1680
1681         case NDISC_REDIRECT:
1682                 ndisc_redirect_rcv(skb);
1683                 break;
1684         }
1685
1686         return 0;
1687 }
1688
1689 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1690 {
1691         struct net_device *dev = ptr;
1692         struct net *net = dev_net(dev);
1693
1694         switch (event) {
1695         case NETDEV_CHANGEADDR:
1696                 neigh_changeaddr(&nd_tbl, dev);
1697                 fib6_run_gc(~0UL, net);
1698                 break;
1699         case NETDEV_DOWN:
1700                 neigh_ifdown(&nd_tbl, dev);
1701                 fib6_run_gc(~0UL, net);
1702                 break;
1703         default:
1704                 break;
1705         }
1706
1707         return NOTIFY_DONE;
1708 }
1709
1710 static struct notifier_block ndisc_netdev_notifier = {
1711         .notifier_call = ndisc_netdev_event,
1712 };
1713
1714 #ifdef CONFIG_SYSCTL
1715 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1716                                          const char *func, const char *dev_name)
1717 {
1718         static char warncomm[TASK_COMM_LEN];
1719         static int warned;
1720         if (strcmp(warncomm, current->comm) && warned < 5) {
1721                 strcpy(warncomm, current->comm);
1722                 printk(KERN_WARNING
1723                         "process `%s' is using deprecated sysctl (%s) "
1724                         "net.ipv6.neigh.%s.%s; "
1725                         "Use net.ipv6.neigh.%s.%s_ms "
1726                         "instead.\n",
1727                         warncomm, func,
1728                         dev_name, ctl->procname,
1729                         dev_name, ctl->procname);
1730                 warned++;
1731         }
1732 }
1733
1734 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, struct file * filp, void __user *buffer, size_t *lenp, loff_t *ppos)
1735 {
1736         struct net_device *dev = ctl->extra1;
1737         struct inet6_dev *idev;
1738         int ret;
1739
1740         if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1741             (strcmp(ctl->procname, "base_reachable_time") == 0))
1742                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1743
1744         if (strcmp(ctl->procname, "retrans_time") == 0)
1745                 ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
1746
1747         else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1748                 ret = proc_dointvec_jiffies(ctl, write,
1749                                             filp, buffer, lenp, ppos);
1750
1751         else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1752                  (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1753                 ret = proc_dointvec_ms_jiffies(ctl, write,
1754                                                filp, buffer, lenp, ppos);
1755         else
1756                 ret = -1;
1757
1758         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1759                 if (ctl->data == &idev->nd_parms->base_reachable_time)
1760                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1761                 idev->tstamp = jiffies;
1762                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1763                 in6_dev_put(idev);
1764         }
1765         return ret;
1766 }
1767
1768 int ndisc_ifinfo_sysctl_strategy(ctl_table *ctl,
1769                                  void __user *oldval, size_t __user *oldlenp,
1770                                  void __user *newval, size_t newlen)
1771 {
1772         struct net_device *dev = ctl->extra1;
1773         struct inet6_dev *idev;
1774         int ret;
1775
1776         if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1777             ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1778                 ndisc_warn_deprecated_sysctl(ctl, "procfs", dev ? dev->name : "default");
1779
1780         switch (ctl->ctl_name) {
1781         case NET_NEIGH_REACHABLE_TIME:
1782                 ret = sysctl_jiffies(ctl, oldval, oldlenp, newval, newlen);
1783                 break;
1784         case NET_NEIGH_RETRANS_TIME_MS:
1785         case NET_NEIGH_REACHABLE_TIME_MS:
1786                  ret = sysctl_ms_jiffies(ctl, oldval, oldlenp, newval, newlen);
1787                  break;
1788         default:
1789                 ret = 0;
1790         }
1791
1792         if (newval && newlen && ret > 0 &&
1793             dev && (idev = in6_dev_get(dev)) != NULL) {
1794                 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1795                     ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1796                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1797                 idev->tstamp = jiffies;
1798                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1799                 in6_dev_put(idev);
1800         }
1801
1802         return ret;
1803 }
1804
1805 #endif
1806
1807 static int ndisc_net_init(struct net *net)
1808 {
1809         struct ipv6_pinfo *np;
1810         struct sock *sk;
1811         int err;
1812
1813         err = inet_ctl_sock_create(&sk, PF_INET6,
1814                                    SOCK_RAW, IPPROTO_ICMPV6, net);
1815         if (err < 0) {
1816                 ND_PRINTK0(KERN_ERR
1817                            "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1818                            err);
1819                 return err;
1820         }
1821
1822         net->ipv6.ndisc_sk = sk;
1823
1824         np = inet6_sk(sk);
1825         np->hop_limit = 255;
1826         /* Do not loopback ndisc messages */
1827         np->mc_loop = 0;
1828
1829         return 0;
1830 }
1831
1832 static void ndisc_net_exit(struct net *net)
1833 {
1834         inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1835 }
1836
1837 static struct pernet_operations ndisc_net_ops = {
1838         .init = ndisc_net_init,
1839         .exit = ndisc_net_exit,
1840 };
1841
1842 int __init ndisc_init(void)
1843 {
1844         int err;
1845
1846         err = register_pernet_subsys(&ndisc_net_ops);
1847         if (err)
1848                 return err;
1849         /*
1850          * Initialize the neighbour table
1851          */
1852         neigh_table_init(&nd_tbl);
1853
1854 #ifdef CONFIG_SYSCTL
1855         err = neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6,
1856                                     NET_IPV6_NEIGH, "ipv6",
1857                                     &ndisc_ifinfo_sysctl_change,
1858                                     &ndisc_ifinfo_sysctl_strategy);
1859         if (err)
1860                 goto out_unregister_pernet;
1861 #endif
1862         err = register_netdevice_notifier(&ndisc_netdev_notifier);
1863         if (err)
1864                 goto out_unregister_sysctl;
1865 out:
1866         return err;
1867
1868 out_unregister_sysctl:
1869 #ifdef CONFIG_SYSCTL
1870         neigh_sysctl_unregister(&nd_tbl.parms);
1871 out_unregister_pernet:
1872 #endif
1873         unregister_pernet_subsys(&ndisc_net_ops);
1874         goto out;
1875 }
1876
1877 void ndisc_cleanup(void)
1878 {
1879         unregister_netdevice_notifier(&ndisc_netdev_notifier);
1880 #ifdef CONFIG_SYSCTL
1881         neigh_sysctl_unregister(&nd_tbl.parms);
1882 #endif
1883         neigh_table_clear(&nd_tbl);
1884         unregister_pernet_subsys(&ndisc_net_ops);
1885 }