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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  *      Lars Fenneberg                  :       fixed MTU setting on receipt
  19  *                                              of an RA.
  20  *
  21  *      Janos Farkas                    :       kmalloc failure checks
  22  *      Alexey Kuznetsov                :       state machine reworked
  23  *                                              and moved to net/core.
  24  *      Pekka Savola                    :       RFC2461 validation
  25  *      YOSHIFUJI Hideaki @USAGI        :       Verify ND options properly
  26  */
  27
  28 /* Set to 3 to get tracing... */
  29 #define ND_DEBUG 1
  30
  31 #define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0)
  32 #define ND_NOPRINTK(x...) do { ; } while(0)
  33 #define ND_PRINTK0 ND_PRINTK
  34 #define ND_PRINTK1 ND_NOPRINTK
  35 #define ND_PRINTK2 ND_NOPRINTK
  36 #define ND_PRINTK3 ND_NOPRINTK
  37 #if ND_DEBUG >= 1
  38 #undef ND_PRINTK1
  39 #define ND_PRINTK1 ND_PRINTK
  40 #endif
  41 #if ND_DEBUG >= 2
  42 #undef ND_PRINTK2
  43 #define ND_PRINTK2 ND_PRINTK
  44 #endif
  45 #if ND_DEBUG >= 3
  46 #undef ND_PRINTK3
  47 #define ND_PRINTK3 ND_PRINTK
  48 #endif
  49
  50 #include <linux/module.h>
  51 #include <linux/errno.h>
  52 #include <linux/types.h>
  53 #include <linux/socket.h>
  54 #include <linux/sockios.h>
  55 #include <linux/sched.h>
  56 #include <linux/net.h>
  57 #include <linux/in6.h>
  58 #include <linux/route.h>
  59 #include <linux/init.h>
  60 #include <linux/rcupdate.h>
  61 #ifdef CONFIG_SYSCTL
  62 #include <linux/sysctl.h>
  63 #endif
  64
  65 #include <linux/if_addr.h>
  66 #include <linux/if_arp.h>
  67 #include <linux/ipv6.h>
  68 #include <linux/icmpv6.h>
  69 #include <linux/jhash.h>
  70
  71 #include <net/sock.h>
  72 #include <net/snmp.h>
  73
  74 #include <net/ipv6.h>
  75 #include <net/protocol.h>
  76 #include <net/ndisc.h>
  77 #include <net/ip6_route.h>
  78 #include <net/addrconf.h>
  79 #include <net/icmp.h>
  80
  81 #include <net/flow.h>
  82 #include <net/ip6_checksum.h>
  83 #include <linux/proc_fs.h>
  84
  85 #include <linux/netfilter.h>
  86 #include <linux/netfilter_ipv6.h>
  87
  88 static struct socket *ndisc_socket;
  89
  90 static u32 ndisc_hash(const void *pkey, const struct net_device *dev);
  91 static int ndisc_constructor(struct neighbour *neigh);
  92 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
  93 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
  94 static int pndisc_constructor(struct pneigh_entry *n);
  95 static void pndisc_destructor(struct pneigh_entry *n);
  96 static void pndisc_redo(struct sk_buff *skb);
  97
  98 static struct neigh_ops ndisc_generic_ops = {
  99         .family =               AF_INET6,
 100         .solicit =              ndisc_solicit,
 101         .error_report =         ndisc_error_report,
 102         .output =               neigh_resolve_output,
 103         .connected_output =     neigh_connected_output,
 104         .hh_output =            dev_queue_xmit,
 105         .queue_xmit =           dev_queue_xmit,
 106 };
 107
 108 static struct neigh_ops ndisc_hh_ops = {
 109         .family =               AF_INET6,
 110         .solicit =              ndisc_solicit,
 111         .error_report =         ndisc_error_report,
 112         .output =               neigh_resolve_output,
 113         .connected_output =     neigh_resolve_output,
 114         .hh_output =            dev_queue_xmit,
 115         .queue_xmit =           dev_queue_xmit,
 116 };
 117
 118
 119 static struct neigh_ops ndisc_direct_ops = {
 120         .family =               AF_INET6,
 121         .output =               dev_queue_xmit,
 122         .connected_output =     dev_queue_xmit,
 123         .hh_output =            dev_queue_xmit,
 124         .queue_xmit =           dev_queue_xmit,
 125 };
 126
 127 struct neigh_table nd_tbl = {
 128         .family =       AF_INET6,
 129         .entry_size =   sizeof(struct neighbour) + sizeof(struct in6_addr),
 130         .key_len =      sizeof(struct in6_addr),
 131         .hash =         ndisc_hash,
 132         .constructor =  ndisc_constructor,
 133         .pconstructor = pndisc_constructor,
 134         .pdestructor =  pndisc_destructor,
 135         .proxy_redo =   pndisc_redo,
 136         .id =           "ndisc_cache",
 137         .parms = {
 138                 .tbl =                  &nd_tbl,
 139                 .base_reachable_time =  30 * HZ,
 140                 .retrans_time =  1 * HZ,
 141                 .gc_staletime = 60 * HZ,
 142                 .reachable_time =               30 * HZ,
 143                 .delay_probe_time =      5 * HZ,
 144                 .queue_len =             3,
 145                 .ucast_probes =  3,
 146                 .mcast_probes =  3,
 147                 .anycast_delay =         1 * HZ,
 148                 .proxy_delay =          (8 * HZ) / 10,
 149                 .proxy_qlen =           64,
 150         },
 151         .gc_interval =    30 * HZ,
 152         .gc_thresh1 =    128,
 153         .gc_thresh2 =    512,
 154         .gc_thresh3 =   1024,
 155 };
 156
 157 /* ND options */
 158 struct ndisc_options {
 159         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 160 #ifdef CONFIG_IPV6_ROUTE_INFO
 161         struct nd_opt_hdr *nd_opts_ri;
 162         struct nd_opt_hdr *nd_opts_ri_end;
 163 #endif
 164 };
 165
 166 #define nd_opts_src_lladdr      nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
 167 #define nd_opts_tgt_lladdr      nd_opt_array[ND_OPT_TARGET_LL_ADDR]
 168 #define nd_opts_pi              nd_opt_array[ND_OPT_PREFIX_INFO]
 169 #define nd_opts_pi_end          nd_opt_array[__ND_OPT_PREFIX_INFO_END]
 170 #define nd_opts_rh              nd_opt_array[ND_OPT_REDIRECT_HDR]
 171 #define nd_opts_mtu             nd_opt_array[ND_OPT_MTU]
 172
 173 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 174
 175 /*
 176  * Return the padding between the option length and the start of the
 177  * link addr.  Currently only IP-over-InfiniBand needs this, although
 178  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 179  * also need a pad of 2.
 180  */
 181 static int ndisc_addr_option_pad(unsigned short type)
 182 {
 183         switch (type) {
 184         case ARPHRD_INFINIBAND: return 2;
 185         default:                return 0;
 186         }
 187 }
 188
 189 static inline int ndisc_opt_addr_space(struct net_device *dev)
 190 {
 191         return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
 192 }
 193
 194 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
 195                                   unsigned short addr_type)
 196 {
 197         int space = NDISC_OPT_SPACE(data_len);
 198         int pad   = ndisc_addr_option_pad(addr_type);
 199
 200         opt[0] = type;
 201         opt[1] = space>>3;
 202
 203         memset(opt + 2, 0, pad);
 204         opt   += pad;
 205         space -= pad;
 206
 207         memcpy(opt+2, data, data_len);
 208         data_len += 2;
 209         opt += data_len;
 210         if ((space -= data_len) > 0)
 211                 memset(opt, 0, space);
 212         return opt + space;
 213 }
 214
 215 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 216                                             struct nd_opt_hdr *end)
 217 {
 218         int type;
 219         if (!cur || !end || cur >= end)
 220                 return NULL;
 221         type = cur->nd_opt_type;
 222         do {
 223                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
 224         } while(cur < end && cur->nd_opt_type != type);
 225         return (cur <= end && cur->nd_opt_type == type ? cur : NULL);
 226 }
 227
 228 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 229                                                  struct ndisc_options *ndopts)
 230 {
 231         struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 232
 233         if (!nd_opt || opt_len < 0 || !ndopts)
 234                 return NULL;
 235         memset(ndopts, 0, sizeof(*ndopts));
 236         while (opt_len) {
 237                 int l;
 238                 if (opt_len < sizeof(struct nd_opt_hdr))
 239                         return NULL;
 240                 l = nd_opt->nd_opt_len << 3;
 241                 if (opt_len < l || l == 0)
 242                         return NULL;
 243                 switch (nd_opt->nd_opt_type) {
 244                 case ND_OPT_SOURCE_LL_ADDR:
 245                 case ND_OPT_TARGET_LL_ADDR:
 246                 case ND_OPT_MTU:
 247                 case ND_OPT_REDIRECT_HDR:
 248                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 249                                 ND_PRINTK2(KERN_WARNING
 250                                            "%s(): duplicated ND6 option found: type=%d\n",
 251                                            __FUNCTION__,
 252                                            nd_opt->nd_opt_type);
 253                         } else {
 254                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 255                         }
 256                         break;
 257                 case ND_OPT_PREFIX_INFO:
 258                         ndopts->nd_opts_pi_end = nd_opt;
 259                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0)
 260                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 261                         break;
 262 #ifdef CONFIG_IPV6_ROUTE_INFO
 263                 case ND_OPT_ROUTE_INFO:
 264                         ndopts->nd_opts_ri_end = nd_opt;
 265                         if (!ndopts->nd_opts_ri)
 266                                 ndopts->nd_opts_ri = nd_opt;
 267                         break;
 268 #endif
 269                 default:
 270                         /*
 271                          * Unknown options must be silently ignored,
 272                          * to accommodate future extension to the protocol.
 273                          */
 274                         ND_PRINTK2(KERN_NOTICE
 275                                    "%s(): ignored unsupported option; type=%d, len=%d\n",
 276                                    __FUNCTION__,
 277                                    nd_opt->nd_opt_type, nd_opt->nd_opt_len);
 278                 }
 279                 opt_len -= l;
 280                 nd_opt = ((void *)nd_opt) + l;
 281         }
 282         return ndopts;
 283 }
 284
 285 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 286                                       struct net_device *dev)
 287 {
 288         u8 *lladdr = (u8 *)(p + 1);
 289         int lladdrlen = p->nd_opt_len << 3;
 290         int prepad = ndisc_addr_option_pad(dev->type);
 291         if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
 292                 return NULL;
 293         return (lladdr + prepad);
 294 }
 295
 296 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 297 {
 298         switch (dev->type) {
 299         case ARPHRD_ETHER:
 300         case ARPHRD_IEEE802:    /* Not sure. Check it later. --ANK */
 301         case ARPHRD_FDDI:
 302                 ipv6_eth_mc_map(addr, buf);
 303                 return 0;
 304         case ARPHRD_IEEE802_TR:
 305                 ipv6_tr_mc_map(addr,buf);
 306                 return 0;
 307         case ARPHRD_ARCNET:
 308                 ipv6_arcnet_mc_map(addr, buf);
 309                 return 0;
 310         case ARPHRD_INFINIBAND:
 311                 ipv6_ib_mc_map(addr, buf);
 312                 return 0;
 313         default:
 314                 if (dir) {
 315                         memcpy(buf, dev->broadcast, dev->addr_len);
 316                         return 0;
 317                 }
 318         }
 319         return -EINVAL;
 320 }
 321
 322 static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
 323 {
 324         const u32 *p32 = pkey;
 325         u32 addr_hash, i;
 326
 327         addr_hash = 0;
 328         for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
 329                 addr_hash ^= *p32++;
 330
 331         return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd);
 332 }
 333
 334 static int ndisc_constructor(struct neighbour *neigh)
 335 {
 336         struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
 337         struct net_device *dev = neigh->dev;
 338         struct inet6_dev *in6_dev;
 339         struct neigh_parms *parms;
 340         int is_multicast = ipv6_addr_is_multicast(addr);
 341
 342         rcu_read_lock();
 343         in6_dev = in6_dev_get(dev);
 344         if (in6_dev == NULL) {
 345                 rcu_read_unlock();
 346                 return -EINVAL;
 347         }
 348
 349         parms = in6_dev->nd_parms;
 350         __neigh_parms_put(neigh->parms);
 351         neigh->parms = neigh_parms_clone(parms);
 352         rcu_read_unlock();
 353
 354         neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 355         if (dev->hard_header == NULL) {
 356                 neigh->nud_state = NUD_NOARP;
 357                 neigh->ops = &ndisc_direct_ops;
 358                 neigh->output = neigh->ops->queue_xmit;
 359         } else {
 360                 if (is_multicast) {
 361                         neigh->nud_state = NUD_NOARP;
 362                         ndisc_mc_map(addr, neigh->ha, dev, 1);
 363                 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 364                         neigh->nud_state = NUD_NOARP;
 365                         memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 366                         if (dev->flags&IFF_LOOPBACK)
 367                                 neigh->type = RTN_LOCAL;
 368                 } else if (dev->flags&IFF_POINTOPOINT) {
 369                         neigh->nud_state = NUD_NOARP;
 370                         memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 371                 }
 372                 if (dev->hard_header_cache)
 373                         neigh->ops = &ndisc_hh_ops;
 374                 else
 375                         neigh->ops = &ndisc_generic_ops;
 376                 if (neigh->nud_state&NUD_VALID)
 377                         neigh->output = neigh->ops->connected_output;
 378                 else
 379                         neigh->output = neigh->ops->output;
 380         }
 381         in6_dev_put(in6_dev);
 382         return 0;
 383 }
 384
 385 static int pndisc_constructor(struct pneigh_entry *n)
 386 {
 387         struct in6_addr *addr = (struct in6_addr*)&n->key;
 388         struct in6_addr maddr;
 389         struct net_device *dev = n->dev;
 390
 391         if (dev == NULL || __in6_dev_get(dev) == NULL)
 392                 return -EINVAL;
 393         addrconf_addr_solict_mult(addr, &maddr);
 394         ipv6_dev_mc_inc(dev, &maddr);
 395         return 0;
 396 }
 397
 398 static void pndisc_destructor(struct pneigh_entry *n)
 399 {
 400         struct in6_addr *addr = (struct in6_addr*)&n->key;
 401         struct in6_addr maddr;
 402         struct net_device *dev = n->dev;
 403
 404         if (dev == NULL || __in6_dev_get(dev) == NULL)
 405                 return;
 406         addrconf_addr_solict_mult(addr, &maddr);
 407         ipv6_dev_mc_dec(dev, &maddr);
 408 }
 409
 410 /*
 411  *      Send a Neighbour Advertisement
 412  */
 413
 414 static inline void ndisc_flow_init(struct flowi *fl, u8 type,
 415                             struct in6_addr *saddr, struct in6_addr *daddr,
 416                             int oif)
 417 {
 418         memset(fl, 0, sizeof(*fl));
 419         ipv6_addr_copy(&fl->fl6_src, saddr);
 420         ipv6_addr_copy(&fl->fl6_dst, daddr);
 421         fl->proto               = IPPROTO_ICMPV6;
 422         fl->fl_icmp_type        = type;
 423         fl->fl_icmp_code        = 0;
 424         fl->oif                 = oif;
 425         security_sk_classify_flow(ndisc_socket->sk, fl);
 426 }
 427
 428 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
 429                    struct in6_addr *daddr, struct in6_addr *solicited_addr,
 430                    int router, int solicited, int override, int inc_opt)
 431 {
 432         struct in6_addr tmpaddr;
 433         struct inet6_ifaddr *ifp;
 434         struct inet6_dev *idev;
 435         struct flowi fl;
 436         struct dst_entry* dst;
 437         struct sock *sk = ndisc_socket->sk;
 438         struct in6_addr *src_addr;
 439         struct nd_msg *msg;
 440         int len;
 441         struct sk_buff *skb;
 442         int err;
 443
 444         len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
 445
 446         /* for anycast or proxy, solicited_addr != src_addr */
 447         ifp = ipv6_get_ifaddr(solicited_addr, dev, 1);
 448         if (ifp) {
 449                 src_addr = solicited_addr;
 450                 in6_ifa_put(ifp);
 451         } else {
 452                 if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr))
 453                         return;
 454                 src_addr = &tmpaddr;
 455         }
 456
 457         ndisc_flow_init(&fl, NDISC_NEIGHBOUR_ADVERTISEMENT, src_addr, daddr,
 458                         dev->ifindex);
 459
 460         dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
 461         if (!dst)
 462                 return;
 463
 464         err = xfrm_lookup(&dst, &fl, NULL, 0);
 465         if (err < 0)
 466                 return;
 467
 468         if (inc_opt) {
 469                 if (dev->addr_len)
 470                         len += ndisc_opt_addr_space(dev);
 471                 else
 472                         inc_opt = 0;
 473         }
 474
 475         skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
 476                                   1, &err);
 477
 478         if (skb == NULL) {
 479                 ND_PRINTK0(KERN_ERR
 480                            "ICMPv6 NA: %s() failed to allocate an skb.\n",
 481                            __FUNCTION__);
 482                 dst_release(dst);
 483                 return;
 484         }
 485
 486         skb_reserve(skb, LL_RESERVED_SPACE(dev));
 487         ip6_nd_hdr(sk, skb, dev, src_addr, daddr, IPPROTO_ICMPV6, len);
 488
 489         msg = (struct nd_msg *)skb_put(skb, len);
 490         skb->h.raw = (unsigned char*)msg;
 491
 492         msg->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
 493         msg->icmph.icmp6_code = 0;
 494         msg->icmph.icmp6_cksum = 0;
 495
 496         msg->icmph.icmp6_unused = 0;
 497         msg->icmph.icmp6_router    = router;
 498         msg->icmph.icmp6_solicited = solicited;
 499         msg->icmph.icmp6_override  = !!override;
 500
 501         /* Set the target address. */
 502         ipv6_addr_copy(&msg->target, solicited_addr);
 503
 504         if (inc_opt)
 505                 ndisc_fill_addr_option(msg->opt, ND_OPT_TARGET_LL_ADDR, dev->dev_addr,
 506                                        dev->addr_len, dev->type);
 507
 508         /* checksum */
 509         msg->icmph.icmp6_cksum = csum_ipv6_magic(src_addr, daddr, len,
 510                                                  IPPROTO_ICMPV6,
 511                                                  csum_partial((__u8 *) msg,
 512                                                               len, 0));
 513
 514         skb->dst = dst;
 515         idev = in6_dev_get(dst->dev);
 516         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
 517         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
 518         if (!err) {
 519                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTNEIGHBORADVERTISEMENTS);
 520                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
 521         }
 522
 523         if (likely(idev != NULL))
 524                 in6_dev_put(idev);
 525 }
 526
 527 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
 528                    struct in6_addr *solicit,
 529                    struct in6_addr *daddr, struct in6_addr *saddr)
 530 {
 531         struct flowi fl;
 532         struct dst_entry* dst;
 533         struct inet6_dev *idev;
 534         struct sock *sk = ndisc_socket->sk;
 535         struct sk_buff *skb;
 536         struct nd_msg *msg;
 537         struct in6_addr addr_buf;
 538         int len;
 539         int err;
 540         int send_llinfo;
 541
 542         if (saddr == NULL) {
 543                 if (ipv6_get_lladdr(dev, &addr_buf))
 544                         return;
 545                 saddr = &addr_buf;
 546         }
 547
 548         ndisc_flow_init(&fl, NDISC_NEIGHBOUR_SOLICITATION, saddr, daddr,
 549                         dev->ifindex);
 550
 551         dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
 552         if (!dst)
 553                 return;
 554
 555         err = xfrm_lookup(&dst, &fl, NULL, 0);
 556         if (err < 0)
 557                 return;
 558
 559         len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
 560         send_llinfo = dev->addr_len && !ipv6_addr_any(saddr);
 561         if (send_llinfo)
 562                 len += ndisc_opt_addr_space(dev);
 563
 564         skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
 565                                   1, &err);
 566         if (skb == NULL) {
 567                 ND_PRINTK0(KERN_ERR
 568                            "ICMPv6 NA: %s() failed to allocate an skb.\n",
 569                            __FUNCTION__);
 570                 dst_release(dst);
 571                 return;
 572         }
 573
 574         skb_reserve(skb, LL_RESERVED_SPACE(dev));
 575         ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 576
 577         msg = (struct nd_msg *)skb_put(skb, len);
 578         skb->h.raw = (unsigned char*)msg;
 579         msg->icmph.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION;
 580         msg->icmph.icmp6_code = 0;
 581         msg->icmph.icmp6_cksum = 0;
 582         msg->icmph.icmp6_unused = 0;
 583
 584         /* Set the target address. */
 585         ipv6_addr_copy(&msg->target, solicit);
 586
 587         if (send_llinfo)
 588                 ndisc_fill_addr_option(msg->opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
 589                                        dev->addr_len, dev->type);
 590
 591         /* checksum */
 592         msg->icmph.icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr,
 593                                                  daddr, len,
 594                                                  IPPROTO_ICMPV6,
 595                                                  csum_partial((__u8 *) msg,
 596                                                               len, 0));
 597         /* send it! */
 598         skb->dst = dst;
 599         idev = in6_dev_get(dst->dev);
 600         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
 601         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
 602         if (!err) {
 603                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTNEIGHBORSOLICITS);
 604                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
 605         }
 606
 607         if (likely(idev != NULL))
 608                 in6_dev_put(idev);
 609 }
 610
 611 void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
 612                    struct in6_addr *daddr)
 613 {
 614         struct flowi fl;
 615         struct dst_entry* dst;
 616         struct inet6_dev *idev;
 617         struct sock *sk = ndisc_socket->sk;
 618         struct sk_buff *skb;
 619         struct icmp6hdr *hdr;
 620         __u8 * opt;
 621         int len;
 622         int err;
 623
 624         ndisc_flow_init(&fl, NDISC_ROUTER_SOLICITATION, saddr, daddr,
 625                         dev->ifindex);
 626
 627         dst = ndisc_dst_alloc(dev, NULL, daddr, ip6_output);
 628         if (!dst)
 629                 return;
 630
 631         err = xfrm_lookup(&dst, &fl, NULL, 0);
 632         if (err < 0)
 633                 return;
 634
 635         len = sizeof(struct icmp6hdr);
 636         if (dev->addr_len)
 637                 len += ndisc_opt_addr_space(dev);
 638
 639         skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
 640                                   1, &err);
 641         if (skb == NULL) {
 642                 ND_PRINTK0(KERN_ERR
 643                            "ICMPv6 RS: %s() failed to allocate an skb.\n",
 644                            __FUNCTION__);
 645                 dst_release(dst);
 646                 return;
 647         }
 648
 649         skb_reserve(skb, LL_RESERVED_SPACE(dev));
 650         ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 651
 652         hdr = (struct icmp6hdr *)skb_put(skb, len);
 653         skb->h.raw = (unsigned char*)hdr;
 654         hdr->icmp6_type = NDISC_ROUTER_SOLICITATION;
 655         hdr->icmp6_code = 0;
 656         hdr->icmp6_cksum = 0;
 657         hdr->icmp6_unused = 0;
 658
 659         opt = (u8*) (hdr + 1);
 660
 661         if (dev->addr_len)
 662                 ndisc_fill_addr_option(opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
 663                                        dev->addr_len, dev->type);
 664
 665         /* checksum */
 666         hdr->icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr, daddr, len,
 667                                            IPPROTO_ICMPV6,
 668                                            csum_partial((__u8 *) hdr, len, 0));
 669
 670         /* send it! */
 671         skb->dst = dst;
 672         idev = in6_dev_get(dst->dev);
 673         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
 674         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
 675         if (!err) {
 676                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTROUTERSOLICITS);
 677                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
 678         }
 679
 680         if (likely(idev != NULL))
 681                 in6_dev_put(idev);
 682 }
 683
 684
 685 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 686 {
 687         /*
 688          *      "The sender MUST return an ICMP
 689          *       destination unreachable"
 690          */
 691         dst_link_failure(skb);
 692         kfree_skb(skb);
 693 }
 694
 695 /* Called with locked neigh: either read or both */
 696
 697 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 698 {
 699         struct in6_addr *saddr = NULL;
 700         struct in6_addr mcaddr;
 701         struct net_device *dev = neigh->dev;
 702         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 703         int probes = atomic_read(&neigh->probes);
 704
 705         if (skb && ipv6_chk_addr(&skb->nh.ipv6h->saddr, dev, 1))
 706                 saddr = &skb->nh.ipv6h->saddr;
 707
 708         if ((probes -= neigh->parms->ucast_probes) < 0) {
 709                 if (!(neigh->nud_state & NUD_VALID)) {
 710                         ND_PRINTK1(KERN_DEBUG
 711                                    "%s(): trying to ucast probe in NUD_INVALID: "
 712                                    NIP6_FMT "\n",
 713                                    __FUNCTION__,
 714                                    NIP6(*target));
 715                 }
 716                 ndisc_send_ns(dev, neigh, target, target, saddr);
 717         } else if ((probes -= neigh->parms->app_probes) < 0) {
 718 #ifdef CONFIG_ARPD
 719                 neigh_app_ns(neigh);
 720 #endif
 721         } else {
 722                 addrconf_addr_solict_mult(target, &mcaddr);
 723                 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
 724         }
 725 }
 726
 727 static void ndisc_recv_ns(struct sk_buff *skb)
 728 {
 729         struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
 730         struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
 731         struct in6_addr *daddr = &skb->nh.ipv6h->daddr;
 732         u8 *lladdr = NULL;
 733         u32 ndoptlen = skb->tail - msg->opt;
 734         struct ndisc_options ndopts;
 735         struct net_device *dev = skb->dev;
 736         struct inet6_ifaddr *ifp;
 737         struct inet6_dev *idev = NULL;
 738         struct neighbour *neigh;
 739         struct pneigh_entry *pneigh = NULL;
 740         int dad = ipv6_addr_any(saddr);
 741         int inc;
 742         int is_router;
 743
 744         if (ipv6_addr_is_multicast(&msg->target)) {
 745                 ND_PRINTK2(KERN_WARNING
 746                            "ICMPv6 NS: multicast target address");
 747                 return;
 748         }
 749
 750         /*
 751          * RFC2461 7.1.1:
 752          * DAD has to be destined for solicited node multicast address.
 753          */
 754         if (dad &&
 755             !(daddr->s6_addr32[0] == htonl(0xff020000) &&
 756               daddr->s6_addr32[1] == htonl(0x00000000) &&
 757               daddr->s6_addr32[2] == htonl(0x00000001) &&
 758               daddr->s6_addr [12] == 0xff )) {
 759                 ND_PRINTK2(KERN_WARNING
 760                            "ICMPv6 NS: bad DAD packet (wrong destination)\n");
 761                 return;
 762         }
 763
 764         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 765                 ND_PRINTK2(KERN_WARNING
 766                            "ICMPv6 NS: invalid ND options\n");
 767                 return;
 768         }
 769
 770         if (ndopts.nd_opts_src_lladdr) {
 771                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 772                 if (!lladdr) {
 773                         ND_PRINTK2(KERN_WARNING
 774                                    "ICMPv6 NS: invalid link-layer address length\n");
 775                         return;
 776                 }
 777
 778                 /* RFC2461 7.1.1:
 779                  *      If the IP source address is the unspecified address,
 780                  *      there MUST NOT be source link-layer address option
 781                  *      in the message.
 782                  */
 783                 if (dad) {
 784                         ND_PRINTK2(KERN_WARNING
 785                                    "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
 786                         return;
 787                 }
 788         }
 789
 790         inc = ipv6_addr_is_multicast(daddr);
 791
 792         if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1)) != NULL) {
 793                 if (ifp->flags & IFA_F_TENTATIVE) {
 794                         /* Address is tentative. If the source
 795                            is unspecified address, it is someone
 796                            does DAD, otherwise we ignore solicitations
 797                            until DAD timer expires.
 798                          */
 799                         if (!dad)
 800                                 goto out;
 801                         if (dev->type == ARPHRD_IEEE802_TR) {
 802                                 unsigned char *sadr = skb->mac.raw;
 803                                 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
 804                                     sadr[9] == dev->dev_addr[1] &&
 805                                     sadr[10] == dev->dev_addr[2] &&
 806                                     sadr[11] == dev->dev_addr[3] &&
 807                                     sadr[12] == dev->dev_addr[4] &&
 808                                     sadr[13] == dev->dev_addr[5]) {
 809                                         /* looped-back to us */
 810                                         goto out;
 811                                 }
 812                         }
 813                         addrconf_dad_failure(ifp);
 814                         return;
 815                 }
 816
 817                 idev = ifp->idev;
 818         } else {
 819                 idev = in6_dev_get(dev);
 820                 if (!idev) {
 821                         /* XXX: count this drop? */
 822                         return;
 823                 }
 824
 825                 if (ipv6_chk_acast_addr(dev, &msg->target) ||
 826                     (idev->cnf.forwarding &&
 827                      (pneigh = pneigh_lookup(&nd_tbl,
 828                                              &msg->target, dev, 0)) != NULL)) {
 829                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 830                             skb->pkt_type != PACKET_HOST &&
 831                             inc != 0 &&
 832                             idev->nd_parms->proxy_delay != 0) {
 833                                 /*
 834                                  * for anycast or proxy,
 835                                  * sender should delay its response
 836                                  * by a random time between 0 and
 837                                  * MAX_ANYCAST_DELAY_TIME seconds.
 838                                  * (RFC2461) -- yoshfuji
 839                                  */
 840                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 841                                 if (n)
 842                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 843                                 goto out;
 844                         }
 845                 } else
 846                         goto out;
 847         }
 848
 849         if (pneigh)
 850                 is_router = pneigh->flags & NTF_ROUTER;
 851         else
 852                 is_router = idev->cnf.forwarding;
 853
 854         if (dad) {
 855                 struct in6_addr maddr;
 856
 857                 ipv6_addr_all_nodes(&maddr);
 858                 ndisc_send_na(dev, NULL, &maddr, &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->hard_header) {
 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->h.raw;
 898         struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
 899         struct in6_addr *daddr = &skb->nh.ipv6h->daddr;
 900         u8 *lladdr = NULL;
 901         u32 ndoptlen = skb->tail - msg->opt;
 902         struct ndisc_options ndopts;
 903         struct net_device *dev = skb->dev;
 904         struct inet6_ifaddr *ifp;
 905         struct neighbour *neigh;
 906
 907         if (skb->len < sizeof(struct nd_msg)) {
 908                 ND_PRINTK2(KERN_WARNING
 909                            "ICMPv6 NA: packet too short\n");
 910                 return;
 911         }
 912
 913         if (ipv6_addr_is_multicast(&msg->target)) {
 914                 ND_PRINTK2(KERN_WARNING
 915                            "ICMPv6 NA: target address is multicast.\n");
 916                 return;
 917         }
 918
 919         if (ipv6_addr_is_multicast(daddr) &&
 920             msg->icmph.icmp6_solicited) {
 921                 ND_PRINTK2(KERN_WARNING
 922                            "ICMPv6 NA: solicited NA is multicasted.\n");
 923                 return;
 924         }
 925
 926         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 927                 ND_PRINTK2(KERN_WARNING
 928                            "ICMPv6 NS: invalid ND option\n");
 929                 return;
 930         }
 931         if (ndopts.nd_opts_tgt_lladdr) {
 932                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 933                 if (!lladdr) {
 934                         ND_PRINTK2(KERN_WARNING
 935                                    "ICMPv6 NA: invalid link-layer address length\n");
 936                         return;
 937                 }
 938         }
 939         if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1))) {
 940                 if (ifp->flags & IFA_F_TENTATIVE) {
 941                         addrconf_dad_failure(ifp);
 942                         return;
 943                 }
 944                 /* What should we make now? The advertisement
 945                    is invalid, but ndisc specs say nothing
 946                    about it. It could be misconfiguration, or
 947                    an smart proxy agent tries to help us :-)
 948                  */
 949                 ND_PRINTK1(KERN_WARNING
 950                            "ICMPv6 NA: someone advertises our address on %s!\n",
 951                            ifp->idev->dev->name);
 952                 in6_ifa_put(ifp);
 953                 return;
 954         }
 955         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
 956
 957         if (neigh) {
 958                 u8 old_flags = neigh->flags;
 959
 960                 if (neigh->nud_state & NUD_FAILED)
 961                         goto out;
 962
 963                 /*
 964                  * Don't update the neighbor cache entry on a proxy NA from
 965                  * ourselves because either the proxied node is off link or it
 966                  * has already sent a NA to us.
 967                  */
 968                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
 969                     pneigh_lookup(&nd_tbl, &msg->target, dev, 0))
 970                         goto out;
 971
 972                 neigh_update(neigh, lladdr,
 973                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
 974                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
 975                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
 976                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
 977                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
 978
 979                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
 980                         /*
 981                          * Change: router to host
 982                          */
 983                         struct rt6_info *rt;
 984                         rt = rt6_get_dflt_router(saddr, dev);
 985                         if (rt)
 986                                 ip6_del_rt(rt);
 987                 }
 988
 989 out:
 990                 neigh_release(neigh);
 991         }
 992 }
 993
 994 static void ndisc_recv_rs(struct sk_buff *skb)
 995 {
 996         struct rs_msg *rs_msg = (struct rs_msg *) skb->h.raw;
 997         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
 998         struct neighbour *neigh;
 999         struct inet6_dev *idev;
1000         struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
1001         struct ndisc_options ndopts;
1002         u8 *lladdr = NULL;
1003
1004         if (skb->len < sizeof(*rs_msg))
1005                 return;
1006
1007         idev = in6_dev_get(skb->dev);
1008         if (!idev) {
1009                 if (net_ratelimit())
1010                         ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1011                 return;
1012         }
1013
1014         /* Don't accept RS if we're not in router mode */
1015         if (!idev->cnf.forwarding)
1016                 goto out;
1017
1018         /*
1019          * Don't update NCE if src = ::;
1020          * this implies that the source node has no ip address assigned yet.
1021          */
1022         if (ipv6_addr_any(saddr))
1023                 goto out;
1024
1025         /* Parse ND options */
1026         if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1027                 if (net_ratelimit())
1028                         ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1029                 goto out;
1030         }
1031
1032         if (ndopts.nd_opts_src_lladdr) {
1033                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1034                                              skb->dev);
1035                 if (!lladdr)
1036                         goto out;
1037         }
1038
1039         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1040         if (neigh) {
1041                 neigh_update(neigh, lladdr, NUD_STALE,
1042                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1043                              NEIGH_UPDATE_F_OVERRIDE|
1044                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1045                 neigh_release(neigh);
1046         }
1047 out:
1048         in6_dev_put(idev);
1049 }
1050
1051 static void ndisc_router_discovery(struct sk_buff *skb)
1052 {
1053         struct ra_msg *ra_msg = (struct ra_msg *) skb->h.raw;
1054         struct neighbour *neigh = NULL;
1055         struct inet6_dev *in6_dev;
1056         struct rt6_info *rt = NULL;
1057         int lifetime;
1058         struct ndisc_options ndopts;
1059         int optlen;
1060         unsigned int pref = 0;
1061
1062         __u8 * opt = (__u8 *)(ra_msg + 1);
1063
1064         optlen = (skb->tail - skb->h.raw) - sizeof(struct ra_msg);
1065
1066         if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
1067                 ND_PRINTK2(KERN_WARNING
1068                            "ICMPv6 RA: source address is not link-local.\n");
1069                 return;
1070         }
1071         if (optlen < 0) {
1072                 ND_PRINTK2(KERN_WARNING
1073                            "ICMPv6 RA: packet too short\n");
1074                 return;
1075         }
1076
1077         /*
1078          *      set the RA_RECV flag in the interface
1079          */
1080
1081         in6_dev = in6_dev_get(skb->dev);
1082         if (in6_dev == NULL) {
1083                 ND_PRINTK0(KERN_ERR
1084                            "ICMPv6 RA: can't find inet6 device for %s.\n",
1085                            skb->dev->name);
1086                 return;
1087         }
1088         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) {
1089                 in6_dev_put(in6_dev);
1090                 return;
1091         }
1092
1093         if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1094                 in6_dev_put(in6_dev);
1095                 ND_PRINTK2(KERN_WARNING
1096                            "ICMP6 RA: invalid ND options\n");
1097                 return;
1098         }
1099
1100         if (in6_dev->if_flags & IF_RS_SENT) {
1101                 /*
1102                  *      flag that an RA was received after an RS was sent
1103                  *      out on this interface.
1104                  */
1105                 in6_dev->if_flags |= IF_RA_RCVD;
1106         }
1107
1108         /*
1109          * Remember the managed/otherconf flags from most recently
1110          * received RA message (RFC 2462) -- yoshfuji
1111          */
1112         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1113                                 IF_RA_OTHERCONF)) |
1114                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1115                                         IF_RA_MANAGED : 0) |
1116                                 (ra_msg->icmph.icmp6_addrconf_other ?
1117                                         IF_RA_OTHERCONF : 0);
1118
1119         if (!in6_dev->cnf.accept_ra_defrtr)
1120                 goto skip_defrtr;
1121
1122         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1123
1124 #ifdef CONFIG_IPV6_ROUTER_PREF
1125         pref = ra_msg->icmph.icmp6_router_pref;
1126         /* 10b is handled as if it were 00b (medium) */
1127         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1128             in6_dev->cnf.accept_ra_rtr_pref)
1129                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1130 #endif
1131
1132         rt = rt6_get_dflt_router(&skb->nh.ipv6h->saddr, skb->dev);
1133
1134         if (rt)
1135                 neigh = rt->rt6i_nexthop;
1136
1137         if (rt && lifetime == 0) {
1138                 neigh_clone(neigh);
1139                 ip6_del_rt(rt);
1140                 rt = NULL;
1141         }
1142
1143         if (rt == NULL && lifetime) {
1144                 ND_PRINTK3(KERN_DEBUG
1145                            "ICMPv6 RA: adding default router.\n");
1146
1147                 rt = rt6_add_dflt_router(&skb->nh.ipv6h->saddr, skb->dev, pref);
1148                 if (rt == NULL) {
1149                         ND_PRINTK0(KERN_ERR
1150                                    "ICMPv6 RA: %s() failed to add default route.\n",
1151                                    __FUNCTION__);
1152                         in6_dev_put(in6_dev);
1153                         return;
1154                 }
1155
1156                 neigh = rt->rt6i_nexthop;
1157                 if (neigh == NULL) {
1158                         ND_PRINTK0(KERN_ERR
1159                                    "ICMPv6 RA: %s() got default router without neighbour.\n",
1160                                    __FUNCTION__);
1161                         dst_release(&rt->u.dst);
1162                         in6_dev_put(in6_dev);
1163                         return;
1164                 }
1165                 neigh->flags |= NTF_ROUTER;
1166         } else if (rt) {
1167                 rt->rt6i_flags |= (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1168         }
1169
1170         if (rt)
1171                 rt->rt6i_expires = jiffies + (HZ * lifetime);
1172
1173         if (ra_msg->icmph.icmp6_hop_limit) {
1174                 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1175                 if (rt)
1176                         rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
1177         }
1178
1179 skip_defrtr:
1180
1181         /*
1182          *      Update Reachable Time and Retrans Timer
1183          */
1184
1185         if (in6_dev->nd_parms) {
1186                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1187
1188                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1189                         rtime = (rtime*HZ)/1000;
1190                         if (rtime < HZ/10)
1191                                 rtime = HZ/10;
1192                         in6_dev->nd_parms->retrans_time = rtime;
1193                         in6_dev->tstamp = jiffies;
1194                         inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1195                 }
1196
1197                 rtime = ntohl(ra_msg->reachable_time);
1198                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1199                         rtime = (rtime*HZ)/1000;
1200
1201                         if (rtime < HZ/10)
1202                                 rtime = HZ/10;
1203
1204                         if (rtime != in6_dev->nd_parms->base_reachable_time) {
1205                                 in6_dev->nd_parms->base_reachable_time = rtime;
1206                                 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1207                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1208                                 in6_dev->tstamp = jiffies;
1209                                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1210                         }
1211                 }
1212         }
1213
1214         /*
1215          *      Process options.
1216          */
1217
1218         if (!neigh)
1219                 neigh = __neigh_lookup(&nd_tbl, &skb->nh.ipv6h->saddr,
1220                                        skb->dev, 1);
1221         if (neigh) {
1222                 u8 *lladdr = NULL;
1223                 if (ndopts.nd_opts_src_lladdr) {
1224                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1225                                                      skb->dev);
1226                         if (!lladdr) {
1227                                 ND_PRINTK2(KERN_WARNING
1228                                            "ICMPv6 RA: invalid link-layer address length\n");
1229                                 goto out;
1230                         }
1231                 }
1232                 neigh_update(neigh, lladdr, NUD_STALE,
1233                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1234                              NEIGH_UPDATE_F_OVERRIDE|
1235                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1236                              NEIGH_UPDATE_F_ISROUTER);
1237         }
1238
1239 #ifdef CONFIG_IPV6_ROUTE_INFO
1240         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1241                 struct nd_opt_hdr *p;
1242                 for (p = ndopts.nd_opts_ri;
1243                      p;
1244                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1245                         if (((struct route_info *)p)->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1246                                 continue;
1247                         rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1248                                       &skb->nh.ipv6h->saddr);
1249                 }
1250         }
1251 #endif
1252
1253         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1254                 struct nd_opt_hdr *p;
1255                 for (p = ndopts.nd_opts_pi;
1256                      p;
1257                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1258                         addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1259                 }
1260         }
1261
1262         if (ndopts.nd_opts_mtu) {
1263                 u32 mtu;
1264
1265                 memcpy(&mtu, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1266                 mtu = ntohl(mtu);
1267
1268                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1269                         ND_PRINTK2(KERN_WARNING
1270                                    "ICMPv6 RA: invalid mtu: %d\n",
1271                                    mtu);
1272                 } else if (in6_dev->cnf.mtu6 != mtu) {
1273                         in6_dev->cnf.mtu6 = mtu;
1274
1275                         if (rt)
1276                                 rt->u.dst.metrics[RTAX_MTU-1] = mtu;
1277
1278                         rt6_mtu_change(skb->dev, mtu);
1279                 }
1280         }
1281
1282         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1283                 ND_PRINTK2(KERN_WARNING
1284                            "ICMPv6 RA: invalid RA options");
1285         }
1286 out:
1287         if (rt)
1288                 dst_release(&rt->u.dst);
1289         else if (neigh)
1290                 neigh_release(neigh);
1291         in6_dev_put(in6_dev);
1292 }
1293
1294 static void ndisc_redirect_rcv(struct sk_buff *skb)
1295 {
1296         struct inet6_dev *in6_dev;
1297         struct icmp6hdr *icmph;
1298         struct in6_addr *dest;
1299         struct in6_addr *target;        /* new first hop to destination */
1300         struct neighbour *neigh;
1301         int on_link = 0;
1302         struct ndisc_options ndopts;
1303         int optlen;
1304         u8 *lladdr = NULL;
1305
1306         if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
1307                 ND_PRINTK2(KERN_WARNING
1308                            "ICMPv6 Redirect: source address is not link-local.\n");
1309                 return;
1310         }
1311
1312         optlen = skb->tail - skb->h.raw;
1313         optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1314
1315         if (optlen < 0) {
1316                 ND_PRINTK2(KERN_WARNING
1317                            "ICMPv6 Redirect: packet too short\n");
1318                 return;
1319         }
1320
1321         icmph = (struct icmp6hdr *) skb->h.raw;
1322         target = (struct in6_addr *) (icmph + 1);
1323         dest = target + 1;
1324
1325         if (ipv6_addr_is_multicast(dest)) {
1326                 ND_PRINTK2(KERN_WARNING
1327                            "ICMPv6 Redirect: destination address is multicast.\n");
1328                 return;
1329         }
1330
1331         if (ipv6_addr_equal(dest, target)) {
1332                 on_link = 1;
1333         } else if (!(ipv6_addr_type(target) & IPV6_ADDR_LINKLOCAL)) {
1334                 ND_PRINTK2(KERN_WARNING
1335                            "ICMPv6 Redirect: target address is not link-local.\n");
1336                 return;
1337         }
1338
1339         in6_dev = in6_dev_get(skb->dev);
1340         if (!in6_dev)
1341                 return;
1342         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1343                 in6_dev_put(in6_dev);
1344                 return;
1345         }
1346
1347         /* RFC2461 8.1:
1348          *      The IP source address of the Redirect MUST be the same as the current
1349          *      first-hop router for the specified ICMP Destination Address.
1350          */
1351
1352         if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1353                 ND_PRINTK2(KERN_WARNING
1354                            "ICMPv6 Redirect: invalid ND options\n");
1355                 in6_dev_put(in6_dev);
1356                 return;
1357         }
1358         if (ndopts.nd_opts_tgt_lladdr) {
1359                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1360                                              skb->dev);
1361                 if (!lladdr) {
1362                         ND_PRINTK2(KERN_WARNING
1363                                    "ICMPv6 Redirect: invalid link-layer address length\n");
1364                         in6_dev_put(in6_dev);
1365                         return;
1366                 }
1367         }
1368
1369         neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1370         if (neigh) {
1371                 rt6_redirect(dest, &skb->nh.ipv6h->daddr,
1372                              &skb->nh.ipv6h->saddr, neigh, lladdr,
1373                              on_link);
1374                 neigh_release(neigh);
1375         }
1376         in6_dev_put(in6_dev);
1377 }
1378
1379 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1380                          struct in6_addr *target)
1381 {
1382         struct sock *sk = ndisc_socket->sk;
1383         int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1384         struct sk_buff *buff;
1385         struct icmp6hdr *icmph;
1386         struct in6_addr saddr_buf;
1387         struct in6_addr *addrp;
1388         struct net_device *dev;
1389         struct rt6_info *rt;
1390         struct dst_entry *dst;
1391         struct inet6_dev *idev;
1392         struct flowi fl;
1393         u8 *opt;
1394         int rd_len;
1395         int err;
1396         int hlen;
1397         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1398
1399         dev = skb->dev;
1400
1401         if (ipv6_get_lladdr(dev, &saddr_buf)) {
1402                 ND_PRINTK2(KERN_WARNING
1403                            "ICMPv6 Redirect: no link-local address on %s\n",
1404                            dev->name);
1405                 return;
1406         }
1407
1408         ndisc_flow_init(&fl, NDISC_REDIRECT, &saddr_buf, &skb->nh.ipv6h->saddr,
1409                         dev->ifindex);
1410
1411         dst = ip6_route_output(NULL, &fl);
1412         if (dst == NULL)
1413                 return;
1414
1415         err = xfrm_lookup(&dst, &fl, NULL, 0);
1416         if (err)
1417                 return;
1418
1419         rt = (struct rt6_info *) dst;
1420
1421         if (rt->rt6i_flags & RTF_GATEWAY) {
1422                 ND_PRINTK2(KERN_WARNING
1423                            "ICMPv6 Redirect: destination is not a neighbour.\n");
1424                 dst_release(dst);
1425                 return;
1426         }
1427         if (!xrlim_allow(dst, 1*HZ)) {
1428                 dst_release(dst);
1429                 return;
1430         }
1431
1432         if (dev->addr_len) {
1433                 read_lock_bh(&neigh->lock);
1434                 if (neigh->nud_state & NUD_VALID) {
1435                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1436                         read_unlock_bh(&neigh->lock);
1437                         ha = ha_buf;
1438                         len += ndisc_opt_addr_space(dev);
1439                 } else
1440                         read_unlock_bh(&neigh->lock);
1441         }
1442
1443         rd_len = min_t(unsigned int,
1444                      IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1445         rd_len &= ~0x7;
1446         len += rd_len;
1447
1448         buff = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
1449                                    1, &err);
1450         if (buff == NULL) {
1451                 ND_PRINTK0(KERN_ERR
1452                            "ICMPv6 Redirect: %s() failed to allocate an skb.\n",
1453                            __FUNCTION__);
1454                 dst_release(dst);
1455                 return;
1456         }
1457
1458         hlen = 0;
1459
1460         skb_reserve(buff, LL_RESERVED_SPACE(dev));
1461         ip6_nd_hdr(sk, buff, dev, &saddr_buf, &skb->nh.ipv6h->saddr,
1462                    IPPROTO_ICMPV6, len);
1463
1464         icmph = (struct icmp6hdr *)skb_put(buff, len);
1465         buff->h.raw = (unsigned char*)icmph;
1466
1467         memset(icmph, 0, sizeof(struct icmp6hdr));
1468         icmph->icmp6_type = NDISC_REDIRECT;
1469
1470         /*
1471          *      copy target and destination addresses
1472          */
1473
1474         addrp = (struct in6_addr *)(icmph + 1);
1475         ipv6_addr_copy(addrp, target);
1476         addrp++;
1477         ipv6_addr_copy(addrp, &skb->nh.ipv6h->daddr);
1478
1479         opt = (u8*) (addrp + 1);
1480
1481         /*
1482          *      include target_address option
1483          */
1484
1485         if (ha)
1486                 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1487                                              dev->addr_len, dev->type);
1488
1489         /*
1490          *      build redirect option and copy skb over to the new packet.
1491          */
1492
1493         memset(opt, 0, 8);
1494         *(opt++) = ND_OPT_REDIRECT_HDR;
1495         *(opt++) = (rd_len >> 3);
1496         opt += 6;
1497
1498         memcpy(opt, skb->nh.ipv6h, rd_len - 8);
1499
1500         icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &skb->nh.ipv6h->saddr,
1501                                              len, IPPROTO_ICMPV6,
1502                                              csum_partial((u8 *) icmph, len, 0));
1503
1504         buff->dst = dst;
1505         idev = in6_dev_get(dst->dev);
1506         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
1507         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, buff, NULL, dst->dev, dst_output);
1508         if (!err) {
1509                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTREDIRECTS);
1510                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
1511         }
1512
1513         if (likely(idev != NULL))
1514                 in6_dev_put(idev);
1515 }
1516
1517 static void pndisc_redo(struct sk_buff *skb)
1518 {
1519         ndisc_recv_ns(skb);
1520         kfree_skb(skb);
1521 }
1522
1523 int ndisc_rcv(struct sk_buff *skb)
1524 {
1525         struct nd_msg *msg;
1526
1527         if (!pskb_may_pull(skb, skb->len))
1528                 return 0;
1529
1530         msg = (struct nd_msg *) skb->h.raw;
1531
1532         __skb_push(skb, skb->data-skb->h.raw);
1533
1534         if (skb->nh.ipv6h->hop_limit != 255) {
1535                 ND_PRINTK2(KERN_WARNING
1536                            "ICMPv6 NDISC: invalid hop-limit: %d\n",
1537                            skb->nh.ipv6h->hop_limit);
1538                 return 0;
1539         }
1540
1541         if (msg->icmph.icmp6_code != 0) {
1542                 ND_PRINTK2(KERN_WARNING
1543                            "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1544                            msg->icmph.icmp6_code);
1545                 return 0;
1546         }
1547
1548         memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1549
1550         switch (msg->icmph.icmp6_type) {
1551         case NDISC_NEIGHBOUR_SOLICITATION:
1552                 ndisc_recv_ns(skb);
1553                 break;
1554
1555         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1556                 ndisc_recv_na(skb);
1557                 break;
1558
1559         case NDISC_ROUTER_SOLICITATION:
1560                 ndisc_recv_rs(skb);
1561                 break;
1562
1563         case NDISC_ROUTER_ADVERTISEMENT:
1564                 ndisc_router_discovery(skb);
1565                 break;
1566
1567         case NDISC_REDIRECT:
1568                 ndisc_redirect_rcv(skb);
1569                 break;
1570         };
1571
1572         return 0;
1573 }
1574
1575 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1576 {
1577         struct net_device *dev = ptr;
1578
1579         switch (event) {
1580         case NETDEV_CHANGEADDR:
1581                 neigh_changeaddr(&nd_tbl, dev);
1582                 fib6_run_gc(~0UL);
1583                 break;
1584         case NETDEV_DOWN:
1585                 neigh_ifdown(&nd_tbl, dev);
1586                 fib6_run_gc(~0UL);
1587                 break;
1588         default:
1589                 break;
1590         }
1591
1592         return NOTIFY_DONE;
1593 }
1594
1595 static struct notifier_block ndisc_netdev_notifier = {
1596         .notifier_call = ndisc_netdev_event,
1597 };
1598
1599 #ifdef CONFIG_SYSCTL
1600 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1601                                          const char *func, const char *dev_name)
1602 {
1603         static char warncomm[TASK_COMM_LEN];
1604         static int warned;
1605         if (strcmp(warncomm, current->comm) && warned < 5) {
1606                 strcpy(warncomm, current->comm);
1607                 printk(KERN_WARNING
1608                         "process `%s' is using deprecated sysctl (%s) "
1609                         "net.ipv6.neigh.%s.%s; "
1610                         "Use net.ipv6.neigh.%s.%s_ms "
1611                         "instead.\n",
1612                         warncomm, func,
1613                         dev_name, ctl->procname,
1614                         dev_name, ctl->procname);
1615                 warned++;
1616         }
1617 }
1618
1619 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, struct file * filp, void __user *buffer, size_t *lenp, loff_t *ppos)
1620 {
1621         struct net_device *dev = ctl->extra1;
1622         struct inet6_dev *idev;
1623         int ret;
1624
1625         if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1626             ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1627                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1628
1629         switch (ctl->ctl_name) {
1630         case NET_NEIGH_RETRANS_TIME:
1631                 ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
1632                 break;
1633         case NET_NEIGH_REACHABLE_TIME:
1634                 ret = proc_dointvec_jiffies(ctl, write,
1635                                             filp, buffer, lenp, ppos);
1636                 break;
1637         case NET_NEIGH_RETRANS_TIME_MS:
1638         case NET_NEIGH_REACHABLE_TIME_MS:
1639                 ret = proc_dointvec_ms_jiffies(ctl, write,
1640                                                filp, buffer, lenp, ppos);
1641                 break;
1642         default:
1643                 ret = -1;
1644         }
1645
1646         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1647                 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1648                     ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1649                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1650                 idev->tstamp = jiffies;
1651                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1652                 in6_dev_put(idev);
1653         }
1654         return ret;
1655 }
1656
1657 static int ndisc_ifinfo_sysctl_strategy(ctl_table *ctl, int __user *name,
1658                                         int nlen, void __user *oldval,
1659                                         size_t __user *oldlenp,
1660                                         void __user *newval, size_t newlen,
1661                                         void **context)
1662 {
1663         struct net_device *dev = ctl->extra1;
1664         struct inet6_dev *idev;
1665         int ret;
1666
1667         if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1668             ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1669                 ndisc_warn_deprecated_sysctl(ctl, "procfs", dev ? dev->name : "default");
1670
1671         switch (ctl->ctl_name) {
1672         case NET_NEIGH_REACHABLE_TIME:
1673                 ret = sysctl_jiffies(ctl, name, nlen,
1674                                      oldval, oldlenp, newval, newlen,
1675                                      context);
1676                 break;
1677         case NET_NEIGH_RETRANS_TIME_MS:
1678         case NET_NEIGH_REACHABLE_TIME_MS:
1679                  ret = sysctl_ms_jiffies(ctl, name, nlen,
1680                                          oldval, oldlenp, newval, newlen,
1681                                          context);
1682                  break;
1683         default:
1684                 ret = 0;
1685         }
1686
1687         if (newval && newlen && ret > 0 &&
1688             dev && (idev = in6_dev_get(dev)) != NULL) {
1689                 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1690                     ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1691                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1692                 idev->tstamp = jiffies;
1693                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1694                 in6_dev_put(idev);
1695         }
1696
1697         return ret;
1698 }
1699
1700 #endif
1701
1702 int __init ndisc_init(struct net_proto_family *ops)
1703 {
1704         struct ipv6_pinfo *np;
1705         struct sock *sk;
1706         int err;
1707
1708         err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, &ndisc_socket);
1709         if (err < 0) {
1710                 ND_PRINTK0(KERN_ERR
1711                            "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1712                            err);
1713                 ndisc_socket = NULL; /* For safety. */
1714                 return err;
1715         }
1716
1717         sk = ndisc_socket->sk;
1718         np = inet6_sk(sk);
1719         sk->sk_allocation = GFP_ATOMIC;
1720         np->hop_limit = 255;
1721         /* Do not loopback ndisc messages */
1722         np->mc_loop = 0;
1723         sk->sk_prot->unhash(sk);
1724
1725         /*
1726          * Initialize the neighbour table
1727          */
1728
1729         neigh_table_init(&nd_tbl);
1730
1731 #ifdef CONFIG_SYSCTL
1732         neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH,
1733                               "ipv6",
1734                               &ndisc_ifinfo_sysctl_change,
1735                               &ndisc_ifinfo_sysctl_strategy);
1736 #endif
1737
1738         register_netdevice_notifier(&ndisc_netdev_notifier);
1739         return 0;
1740 }
1741
1742 void ndisc_cleanup(void)
1743 {
1744 #ifdef CONFIG_SYSCTL
1745         neigh_sysctl_unregister(&nd_tbl.parms);
1746 #endif
1747         neigh_table_clear(&nd_tbl);
1748         sock_release(ndisc_socket);
1749         ndisc_socket = NULL; /* For safety. */
1750 }