net/ipv6/ndisc.c

   1 /*
   2  *      Neighbour Discovery for IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *      Mike Shaver             <shaver@ingenia.com>
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License
  11  *      as published by the Free Software Foundation; either version
  12  *      2 of the License, or (at your option) any later version.
  13  */
  14
  15 /*
  16  *      Changes:
  17  *
  18  *      Alexey I. Froloff               :       RFC6106 (DNSSL) support
  19  *      Pierre Ynard                    :       export userland ND options
  20  *                                              through netlink (RDNSS support)
  21  *      Lars Fenneberg                  :       fixed MTU setting on receipt
  22  *                                              of an RA.
  23  *      Janos Farkas                    :       kmalloc failure checks
  24  *      Alexey Kuznetsov                :       state machine reworked
  25  *                                              and moved to net/core.
  26  *      Pekka Savola                    :       RFC2461 validation
  27  *      YOSHIFUJI Hideaki @USAGI        :       Verify ND options properly
  28  */
  29
  30 #define pr_fmt(fmt) "ICMPv6: " fmt
  31
  32 #include <linux/module.h>
  33 #include <linux/errno.h>
  34 #include <linux/types.h>
  35 #include <linux/socket.h>
  36 #include <linux/sockios.h>
  37 #include <linux/sched.h>
  38 #include <linux/net.h>
  39 #include <linux/in6.h>
  40 #include <linux/route.h>
  41 #include <linux/init.h>
  42 #include <linux/rcupdate.h>
  43 #include <linux/slab.h>
  44 #ifdef CONFIG_SYSCTL
  45 #include <linux/sysctl.h>
  46 #endif
  47
  48 #include <linux/if_addr.h>
  49 #include <linux/if_arp.h>
  50 #include <linux/ipv6.h>
  51 #include <linux/icmpv6.h>
  52 #include <linux/jhash.h>
  53
  54 #include <net/sock.h>
  55 #include <net/snmp.h>
  56
  57 #include <net/ipv6.h>
  58 #include <net/protocol.h>
  59 #include <net/ndisc.h>
  60 #include <net/ip6_route.h>
  61 #include <net/addrconf.h>
  62 #include <net/icmp.h>
  63
  64 #include <net/netlink.h>
  65 #include <linux/rtnetlink.h>
  66
  67 #include <net/flow.h>
  68 #include <net/ip6_checksum.h>
  69 #include <net/inet_common.h>
  70 #include <linux/proc_fs.h>
  71
  72 #include <linux/netfilter.h>
  73 #include <linux/netfilter_ipv6.h>
  74
  75 /* Set to 3 to get tracing... */
  76 #define ND_DEBUG 1
  77
  78 #define ND_PRINTK(val, level, fmt, ...)                         \
  79 do {                                                            \
  80         if (val <= ND_DEBUG)                                    \
  81                 net_##level##_ratelimited(fmt, ##__VA_ARGS__);  \
  82 } while (0)
  83
  84 static u32 ndisc_hash(const void *pkey,
  85                       const struct net_device *dev,
  86                       __u32 *hash_rnd);
  87 static int ndisc_constructor(struct neighbour *neigh);
  88 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
  89 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
  90 static int pndisc_constructor(struct pneigh_entry *n);
  91 static void pndisc_destructor(struct pneigh_entry *n);
  92 static void pndisc_redo(struct sk_buff *skb);
  93
  94 static const struct neigh_ops ndisc_generic_ops = {
  95         .family =               AF_INET6,
  96         .solicit =              ndisc_solicit,
  97         .error_report =         ndisc_error_report,
  98         .output =               neigh_resolve_output,
  99         .connected_output =     neigh_connected_output,
 100 };
 101
 102 static const struct neigh_ops ndisc_hh_ops = {
 103         .family =               AF_INET6,
 104         .solicit =              ndisc_solicit,
 105         .error_report =         ndisc_error_report,
 106         .output =               neigh_resolve_output,
 107         .connected_output =     neigh_resolve_output,
 108 };
 109
 110
 111 static const struct neigh_ops ndisc_direct_ops = {
 112         .family =               AF_INET6,
 113         .output =               neigh_direct_output,
 114         .connected_output =     neigh_direct_output,
 115 };
 116
 117 struct neigh_table nd_tbl = {
 118         .family =       AF_INET6,
 119         .key_len =      sizeof(struct in6_addr),
 120         .hash =         ndisc_hash,
 121         .constructor =  ndisc_constructor,
 122         .pconstructor = pndisc_constructor,
 123         .pdestructor =  pndisc_destructor,
 124         .proxy_redo =   pndisc_redo,
 125         .id =           "ndisc_cache",
 126         .parms = {
 127                 .tbl                    = &nd_tbl,
 128                 .base_reachable_time    = ND_REACHABLE_TIME,
 129                 .retrans_time           = ND_RETRANS_TIMER,
 130                 .gc_staletime           = 60 * HZ,
 131                 .reachable_time         = ND_REACHABLE_TIME,
 132                 .delay_probe_time       = 5 * HZ,
 133                 .queue_len_bytes        = 64*1024,
 134                 .ucast_probes           = 3,
 135                 .mcast_probes           = 3,
 136                 .anycast_delay          = 1 * HZ,
 137                 .proxy_delay            = (8 * HZ) / 10,
 138                 .proxy_qlen             = 64,
 139         },
 140         .gc_interval =    30 * HZ,
 141         .gc_thresh1 =    128,
 142         .gc_thresh2 =    512,
 143         .gc_thresh3 =   1024,
 144 };
 145
 146 static void ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data)
 147 {
 148         int pad   = ndisc_addr_option_pad(skb->dev->type);
 149         int data_len = skb->dev->addr_len;
 150         int space = ndisc_opt_addr_space(skb->dev);
 151         u8 *opt = skb_put(skb, space);
 152
 153         opt[0] = type;
 154         opt[1] = space>>3;
 155
 156         memset(opt + 2, 0, pad);
 157         opt   += pad;
 158         space -= pad;
 159
 160         memcpy(opt+2, data, data_len);
 161         data_len += 2;
 162         opt += data_len;
 163         if ((space -= data_len) > 0)
 164                 memset(opt, 0, space);
 165 }
 166
 167 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 168                                             struct nd_opt_hdr *end)
 169 {
 170         int type;
 171         if (!cur || !end || cur >= end)
 172                 return NULL;
 173         type = cur->nd_opt_type;
 174         do {
 175                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
 176         } while(cur < end && cur->nd_opt_type != type);
 177         return cur <= end && cur->nd_opt_type == type ? cur : NULL;
 178 }
 179
 180 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
 181 {
 182         return opt->nd_opt_type == ND_OPT_RDNSS ||
 183                 opt->nd_opt_type == ND_OPT_DNSSL;
 184 }
 185
 186 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
 187                                              struct nd_opt_hdr *end)
 188 {
 189         if (!cur || !end || cur >= end)
 190                 return NULL;
 191         do {
 192                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
 193         } while(cur < end && !ndisc_is_useropt(cur));
 194         return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
 195 }
 196
 197 struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 198                                           struct ndisc_options *ndopts)
 199 {
 200         struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 201
 202         if (!nd_opt || opt_len < 0 || !ndopts)
 203                 return NULL;
 204         memset(ndopts, 0, sizeof(*ndopts));
 205         while (opt_len) {
 206                 int l;
 207                 if (opt_len < sizeof(struct nd_opt_hdr))
 208                         return NULL;
 209                 l = nd_opt->nd_opt_len << 3;
 210                 if (opt_len < l || l == 0)
 211                         return NULL;
 212                 switch (nd_opt->nd_opt_type) {
 213                 case ND_OPT_SOURCE_LL_ADDR:
 214                 case ND_OPT_TARGET_LL_ADDR:
 215                 case ND_OPT_MTU:
 216                 case ND_OPT_REDIRECT_HDR:
 217                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 218                                 ND_PRINTK(2, warn,
 219                                           "%s: duplicated ND6 option found: type=%d\n",
 220                                           __func__, nd_opt->nd_opt_type);
 221                         } else {
 222                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 223                         }
 224                         break;
 225                 case ND_OPT_PREFIX_INFO:
 226                         ndopts->nd_opts_pi_end = nd_opt;
 227                         if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 228                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 229                         break;
 230 #ifdef CONFIG_IPV6_ROUTE_INFO
 231                 case ND_OPT_ROUTE_INFO:
 232                         ndopts->nd_opts_ri_end = nd_opt;
 233                         if (!ndopts->nd_opts_ri)
 234                                 ndopts->nd_opts_ri = nd_opt;
 235                         break;
 236 #endif
 237                 default:
 238                         if (ndisc_is_useropt(nd_opt)) {
 239                                 ndopts->nd_useropts_end = nd_opt;
 240                                 if (!ndopts->nd_useropts)
 241                                         ndopts->nd_useropts = nd_opt;
 242                         } else {
 243                                 /*
 244                                  * Unknown options must be silently ignored,
 245                                  * to accommodate future extension to the
 246                                  * protocol.
 247                                  */
 248                                 ND_PRINTK(2, notice,
 249                                           "%s: ignored unsupported option; type=%d, len=%d\n",
 250                                           __func__,
 251                                           nd_opt->nd_opt_type,
 252                                           nd_opt->nd_opt_len);
 253                         }
 254                 }
 255                 opt_len -= l;
 256                 nd_opt = ((void *)nd_opt) + l;
 257         }
 258         return ndopts;
 259 }
 260
 261 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 262 {
 263         switch (dev->type) {
 264         case ARPHRD_ETHER:
 265         case ARPHRD_IEEE802:    /* Not sure. Check it later. --ANK */
 266         case ARPHRD_FDDI:
 267                 ipv6_eth_mc_map(addr, buf);
 268                 return 0;
 269         case ARPHRD_ARCNET:
 270                 ipv6_arcnet_mc_map(addr, buf);
 271                 return 0;
 272         case ARPHRD_INFINIBAND:
 273                 ipv6_ib_mc_map(addr, dev->broadcast, buf);
 274                 return 0;
 275         case ARPHRD_IPGRE:
 276                 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
 277         default:
 278                 if (dir) {
 279                         memcpy(buf, dev->broadcast, dev->addr_len);
 280                         return 0;
 281                 }
 282         }
 283         return -EINVAL;
 284 }
 285
 286 EXPORT_SYMBOL(ndisc_mc_map);
 287
 288 static u32 ndisc_hash(const void *pkey,
 289                       const struct net_device *dev,
 290                       __u32 *hash_rnd)
 291 {
 292         return ndisc_hashfn(pkey, dev, hash_rnd);
 293 }
 294
 295 static int ndisc_constructor(struct neighbour *neigh)
 296 {
 297         struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
 298         struct net_device *dev = neigh->dev;
 299         struct inet6_dev *in6_dev;
 300         struct neigh_parms *parms;
 301         bool is_multicast = ipv6_addr_is_multicast(addr);
 302
 303         in6_dev = in6_dev_get(dev);
 304         if (in6_dev == NULL) {
 305                 return -EINVAL;
 306         }
 307
 308         parms = in6_dev->nd_parms;
 309         __neigh_parms_put(neigh->parms);
 310         neigh->parms = neigh_parms_clone(parms);
 311
 312         neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 313         if (!dev->header_ops) {
 314                 neigh->nud_state = NUD_NOARP;
 315                 neigh->ops = &ndisc_direct_ops;
 316                 neigh->output = neigh_direct_output;
 317         } else {
 318                 if (is_multicast) {
 319                         neigh->nud_state = NUD_NOARP;
 320                         ndisc_mc_map(addr, neigh->ha, dev, 1);
 321                 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 322                         neigh->nud_state = NUD_NOARP;
 323                         memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 324                         if (dev->flags&IFF_LOOPBACK)
 325                                 neigh->type = RTN_LOCAL;
 326                 } else if (dev->flags&IFF_POINTOPOINT) {
 327                         neigh->nud_state = NUD_NOARP;
 328                         memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 329                 }
 330                 if (dev->header_ops->cache)
 331                         neigh->ops = &ndisc_hh_ops;
 332                 else
 333                         neigh->ops = &ndisc_generic_ops;
 334                 if (neigh->nud_state&NUD_VALID)
 335                         neigh->output = neigh->ops->connected_output;
 336                 else
 337                         neigh->output = neigh->ops->output;
 338         }
 339         in6_dev_put(in6_dev);
 340         return 0;
 341 }
 342
 343 static int pndisc_constructor(struct pneigh_entry *n)
 344 {
 345         struct in6_addr *addr = (struct in6_addr*)&n->key;
 346         struct in6_addr maddr;
 347         struct net_device *dev = n->dev;
 348
 349         if (dev == NULL || __in6_dev_get(dev) == NULL)
 350                 return -EINVAL;
 351         addrconf_addr_solict_mult(addr, &maddr);
 352         ipv6_dev_mc_inc(dev, &maddr);
 353         return 0;
 354 }
 355
 356 static void pndisc_destructor(struct pneigh_entry *n)
 357 {
 358         struct in6_addr *addr = (struct in6_addr*)&n->key;
 359         struct in6_addr maddr;
 360         struct net_device *dev = n->dev;
 361
 362         if (dev == NULL || __in6_dev_get(dev) == NULL)
 363                 return;
 364         addrconf_addr_solict_mult(addr, &maddr);
 365         ipv6_dev_mc_dec(dev, &maddr);
 366 }
 367
 368 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 369                                        int len)
 370 {
 371         int hlen = LL_RESERVED_SPACE(dev);
 372         int tlen = dev->needed_tailroom;
 373         struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
 374         struct sk_buff *skb;
 375
 376         skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
 377         if (!skb) {
 378                 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
 379                           __func__);
 380                 return NULL;
 381         }
 382
 383         skb->protocol = htons(ETH_P_IPV6);
 384         skb->dev = dev;
 385
 386         skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
 387         skb_reset_transport_header(skb);
 388
 389         /* Manually assign socket ownership as we avoid calling
 390          * sock_alloc_send_pskb() to bypass wmem buffer limits
 391          */
 392         skb_set_owner_w(skb, sk);
 393
 394         return skb;
 395 }
 396
 397 static void ip6_nd_hdr(struct sk_buff *skb,
 398                        const struct in6_addr *saddr,
 399                        const struct in6_addr *daddr,
 400                        int hop_limit, int len)
 401 {
 402         struct ipv6hdr *hdr;
 403
 404         skb_push(skb, sizeof(*hdr));
 405         skb_reset_network_header(skb);
 406         hdr = ipv6_hdr(skb);
 407
 408         ip6_flow_hdr(hdr, 0, 0);
 409
 410         hdr->payload_len = htons(len);
 411         hdr->nexthdr = IPPROTO_ICMPV6;
 412         hdr->hop_limit = hop_limit;
 413
 414         hdr->saddr = *saddr;
 415         hdr->daddr = *daddr;
 416 }
 417
 418 static void ndisc_send_skb(struct sk_buff *skb,
 419                            const struct in6_addr *daddr,
 420                            const struct in6_addr *saddr)
 421 {
 422         struct dst_entry *dst = skb_dst(skb);
 423         struct net *net = dev_net(skb->dev);
 424         struct sock *sk = net->ipv6.ndisc_sk;
 425         struct inet6_dev *idev;
 426         int err;
 427         struct icmp6hdr *icmp6h = icmp6_hdr(skb);
 428         u8 type;
 429
 430         type = icmp6h->icmp6_type;
 431
 432         if (!dst) {
 433                 struct flowi6 fl6;
 434
 435                 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, skb->dev->ifindex);
 436                 dst = icmp6_dst_alloc(skb->dev, &fl6);
 437                 if (IS_ERR(dst)) {
 438                         kfree_skb(skb);
 439                         return;
 440                 }
 441
 442                 skb_dst_set(skb, dst);
 443         }
 444
 445         icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
 446                                               IPPROTO_ICMPV6,
 447                                               csum_partial(icmp6h,
 448                                                            skb->len, 0));
 449
 450         ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
 451
 452         rcu_read_lock();
 453         idev = __in6_dev_get(dst->dev);
 454         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
 455
 456         err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
 457                       dst_output);
 458         if (!err) {
 459                 ICMP6MSGOUT_INC_STATS(net, idev, type);
 460                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 461         }
 462
 463         rcu_read_unlock();
 464 }
 465
 466 void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
 467                    const struct in6_addr *daddr,
 468                    const struct in6_addr *solicited_addr,
 469                    bool router, bool solicited, bool override, bool inc_opt)
 470 {
 471         struct sk_buff *skb;
 472         struct in6_addr tmpaddr;
 473         struct inet6_ifaddr *ifp;
 474         const struct in6_addr *src_addr;
 475         struct nd_msg *msg;
 476         int optlen = 0;
 477
 478         /* for anycast or proxy, solicited_addr != src_addr */
 479         ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 480         if (ifp) {
 481                 src_addr = solicited_addr;
 482                 if (ifp->flags & IFA_F_OPTIMISTIC)
 483                         override = false;
 484                 inc_opt |= ifp->idev->cnf.force_tllao;
 485                 in6_ifa_put(ifp);
 486         } else {
 487                 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 488                                        inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 489                                        &tmpaddr))
 490                         return;
 491                 src_addr = &tmpaddr;
 492         }
 493
 494         if (!dev->addr_len)
 495                 inc_opt = 0;
 496         if (inc_opt)
 497                 optlen += ndisc_opt_addr_space(dev);
 498
 499         skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 500         if (!skb)
 501                 return;
 502
 503         msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
 504         *msg = (struct nd_msg) {
 505                 .icmph = {
 506                         .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 507                         .icmp6_router = router,
 508                         .icmp6_solicited = solicited,
 509                         .icmp6_override = override,
 510                 },
 511                 .target = *solicited_addr,
 512         };
 513
 514         if (inc_opt)
 515                 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
 516                                        dev->dev_addr);
 517
 518
 519         ndisc_send_skb(skb, daddr, src_addr);
 520 }
 521
 522 static void ndisc_send_unsol_na(struct net_device *dev)
 523 {
 524         struct inet6_dev *idev;
 525         struct inet6_ifaddr *ifa;
 526
 527         idev = in6_dev_get(dev);
 528         if (!idev)
 529                 return;
 530
 531         read_lock_bh(&idev->lock);
 532         list_for_each_entry(ifa, &idev->addr_list, if_list) {
 533                 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &ifa->addr,
 534                               /*router=*/ !!idev->cnf.forwarding,
 535                               /*solicited=*/ false, /*override=*/ true,
 536                               /*inc_opt=*/ true);
 537         }
 538         read_unlock_bh(&idev->lock);
 539
 540         in6_dev_put(idev);
 541 }
 542
 543 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
 544                    const struct in6_addr *solicit,
 545                    const struct in6_addr *daddr, const struct in6_addr *saddr)
 546 {
 547         struct sk_buff *skb;
 548         struct in6_addr addr_buf;
 549         int inc_opt = dev->addr_len;
 550         int optlen = 0;
 551         struct nd_msg *msg;
 552
 553         if (saddr == NULL) {
 554                 if (ipv6_get_lladdr(dev, &addr_buf,
 555                                    (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 556                         return;
 557                 saddr = &addr_buf;
 558         }
 559
 560         if (ipv6_addr_any(saddr))
 561                 inc_opt = false;
 562         if (inc_opt)
 563                 optlen += ndisc_opt_addr_space(dev);
 564
 565         skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 566         if (!skb)
 567                 return;
 568
 569         msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
 570         *msg = (struct nd_msg) {
 571                 .icmph = {
 572                         .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 573                 },
 574                 .target = *solicit,
 575         };
 576
 577         if (inc_opt)
 578                 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 579                                        dev->dev_addr);
 580
 581         ndisc_send_skb(skb, daddr, saddr);
 582 }
 583
 584 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 585                    const struct in6_addr *daddr)
 586 {
 587         struct sk_buff *skb;
 588         struct rs_msg *msg;
 589         int send_sllao = dev->addr_len;
 590         int optlen = 0;
 591
 592 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 593         /*
 594          * According to section 2.2 of RFC 4429, we must not
 595          * send router solicitations with a sllao from
 596          * optimistic addresses, but we may send the solicitation
 597          * if we don't include the sllao.  So here we check
 598          * if our address is optimistic, and if so, we
 599          * suppress the inclusion of the sllao.
 600          */
 601         if (send_sllao) {
 602                 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 603                                                            dev, 1);
 604                 if (ifp) {
 605                         if (ifp->flags & IFA_F_OPTIMISTIC)  {
 606                                 send_sllao = 0;
 607                         }
 608                         in6_ifa_put(ifp);
 609                 } else {
 610                         send_sllao = 0;
 611                 }
 612         }
 613 #endif
 614         if (send_sllao)
 615                 optlen += ndisc_opt_addr_space(dev);
 616
 617         skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 618         if (!skb)
 619                 return;
 620
 621         msg = (struct rs_msg *)skb_put(skb, sizeof(*msg));
 622         *msg = (struct rs_msg) {
 623                 .icmph = {
 624                         .icmp6_type = NDISC_ROUTER_SOLICITATION,
 625                 },
 626         };
 627
 628         if (send_sllao)
 629                 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 630                                        dev->dev_addr);
 631
 632         ndisc_send_skb(skb, daddr, saddr);
 633 }
 634
 635
 636 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 637 {
 638         /*
 639          *      "The sender MUST return an ICMP
 640          *       destination unreachable"
 641          */
 642         dst_link_failure(skb);
 643         kfree_skb(skb);
 644 }
 645
 646 /* Called with locked neigh: either read or both */
 647
 648 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 649 {
 650         struct in6_addr *saddr = NULL;
 651         struct in6_addr mcaddr;
 652         struct net_device *dev = neigh->dev;
 653         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 654         int probes = atomic_read(&neigh->probes);
 655
 656         if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
 657                 saddr = &ipv6_hdr(skb)->saddr;
 658
 659         if ((probes -= neigh->parms->ucast_probes) < 0) {
 660                 if (!(neigh->nud_state & NUD_VALID)) {
 661                         ND_PRINTK(1, dbg,
 662                                   "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
 663                                   __func__, target);
 664                 }
 665                 ndisc_send_ns(dev, neigh, target, target, saddr);
 666         } else if ((probes -= neigh->parms->app_probes) < 0) {
 667                 neigh_app_ns(neigh);
 668         } else {
 669                 addrconf_addr_solict_mult(target, &mcaddr);
 670                 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
 671         }
 672 }
 673
 674 static int pndisc_is_router(const void *pkey,
 675                             struct net_device *dev)
 676 {
 677         struct pneigh_entry *n;
 678         int ret = -1;
 679
 680         read_lock_bh(&nd_tbl.lock);
 681         n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 682         if (n)
 683                 ret = !!(n->flags & NTF_ROUTER);
 684         read_unlock_bh(&nd_tbl.lock);
 685
 686         return ret;
 687 }
 688
 689 static void ndisc_recv_ns(struct sk_buff *skb)
 690 {
 691         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 692         const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 693         const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 694         u8 *lladdr = NULL;
 695         u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 696                                     offsetof(struct nd_msg, opt));
 697         struct ndisc_options ndopts;
 698         struct net_device *dev = skb->dev;
 699         struct inet6_ifaddr *ifp;
 700         struct inet6_dev *idev = NULL;
 701         struct neighbour *neigh;
 702         int dad = ipv6_addr_any(saddr);
 703         bool inc;
 704         int is_router = -1;
 705
 706         if (skb->len < sizeof(struct nd_msg)) {
 707                 ND_PRINTK(2, warn, "NS: packet too short\n");
 708                 return;
 709         }
 710
 711         if (ipv6_addr_is_multicast(&msg->target)) {
 712                 ND_PRINTK(2, warn, "NS: multicast target address\n");
 713                 return;
 714         }
 715
 716         /*
 717          * RFC2461 7.1.1:
 718          * DAD has to be destined for solicited node multicast address.
 719          */
 720         if (dad && !ipv6_addr_is_solict_mult(daddr)) {
 721                 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
 722                 return;
 723         }
 724
 725         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 726                 ND_PRINTK(2, warn, "NS: invalid ND options\n");
 727                 return;
 728         }
 729
 730         if (ndopts.nd_opts_src_lladdr) {
 731                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 732                 if (!lladdr) {
 733                         ND_PRINTK(2, warn,
 734                                   "NS: invalid link-layer address length\n");
 735                         return;
 736                 }
 737
 738                 /* RFC2461 7.1.1:
 739                  *      If the IP source address is the unspecified address,
 740                  *      there MUST NOT be source link-layer address option
 741                  *      in the message.
 742                  */
 743                 if (dad) {
 744                         ND_PRINTK(2, warn,
 745                                   "NS: bad DAD packet (link-layer address option)\n");
 746                         return;
 747                 }
 748         }
 749
 750         inc = ipv6_addr_is_multicast(daddr);
 751
 752         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 753         if (ifp) {
 754
 755                 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 756                         if (dad) {
 757                                 /*
 758                                  * We are colliding with another node
 759                                  * who is doing DAD
 760                                  * so fail our DAD process
 761                                  */
 762                                 addrconf_dad_failure(ifp);
 763                                 return;
 764                         } else {
 765                                 /*
 766                                  * This is not a dad solicitation.
 767                                  * If we are an optimistic node,
 768                                  * we should respond.
 769                                  * Otherwise, we should ignore it.
 770                                  */
 771                                 if (!(ifp->flags & IFA_F_OPTIMISTIC))
 772                                         goto out;
 773                         }
 774                 }
 775
 776                 idev = ifp->idev;
 777         } else {
 778                 struct net *net = dev_net(dev);
 779
 780                 idev = in6_dev_get(dev);
 781                 if (!idev) {
 782                         /* XXX: count this drop? */
 783                         return;
 784                 }
 785
 786                 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 787                     (idev->cnf.forwarding &&
 788                      (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
 789                      (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 790                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 791                             skb->pkt_type != PACKET_HOST &&
 792                             inc &&
 793                             idev->nd_parms->proxy_delay != 0) {
 794                                 /*
 795                                  * for anycast or proxy,
 796                                  * sender should delay its response
 797                                  * by a random time between 0 and
 798                                  * MAX_ANYCAST_DELAY_TIME seconds.
 799                                  * (RFC2461) -- yoshfuji
 800                                  */
 801                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 802                                 if (n)
 803                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 804                                 goto out;
 805                         }
 806                 } else
 807                         goto out;
 808         }
 809
 810         if (is_router < 0)
 811                 is_router = idev->cnf.forwarding;
 812
 813         if (dad) {
 814                 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
 815                               !!is_router, false, (ifp != NULL), true);
 816                 goto out;
 817         }
 818
 819         if (inc)
 820                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 821         else
 822                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 823
 824         /*
 825          *      update / create cache entry
 826          *      for the source address
 827          */
 828         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 829                                !inc || lladdr || !dev->addr_len);
 830         if (neigh)
 831                 neigh_update(neigh, lladdr, NUD_STALE,
 832                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
 833                              NEIGH_UPDATE_F_OVERRIDE);
 834         if (neigh || !dev->header_ops) {
 835                 ndisc_send_na(dev, neigh, saddr, &msg->target,
 836                               !!is_router,
 837                               true, (ifp != NULL && inc), inc);
 838                 if (neigh)
 839                         neigh_release(neigh);
 840         }
 841
 842 out:
 843         if (ifp)
 844                 in6_ifa_put(ifp);
 845         else
 846                 in6_dev_put(idev);
 847 }
 848
 849 static void ndisc_recv_na(struct sk_buff *skb)
 850 {
 851         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 852         const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 853         const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 854         u8 *lladdr = NULL;
 855         u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 856                                     offsetof(struct nd_msg, opt));
 857         struct ndisc_options ndopts;
 858         struct net_device *dev = skb->dev;
 859         struct inet6_ifaddr *ifp;
 860         struct neighbour *neigh;
 861
 862         if (skb->len < sizeof(struct nd_msg)) {
 863                 ND_PRINTK(2, warn, "NA: packet too short\n");
 864                 return;
 865         }
 866
 867         if (ipv6_addr_is_multicast(&msg->target)) {
 868                 ND_PRINTK(2, warn, "NA: target address is multicast\n");
 869                 return;
 870         }
 871
 872         if (ipv6_addr_is_multicast(daddr) &&
 873             msg->icmph.icmp6_solicited) {
 874                 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
 875                 return;
 876         }
 877
 878         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 879                 ND_PRINTK(2, warn, "NS: invalid ND option\n");
 880                 return;
 881         }
 882         if (ndopts.nd_opts_tgt_lladdr) {
 883                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 884                 if (!lladdr) {
 885                         ND_PRINTK(2, warn,
 886                                   "NA: invalid link-layer address length\n");
 887                         return;
 888                 }
 889         }
 890         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 891         if (ifp) {
 892                 if (skb->pkt_type != PACKET_LOOPBACK
 893                     && (ifp->flags & IFA_F_TENTATIVE)) {
 894                                 addrconf_dad_failure(ifp);
 895                                 return;
 896                 }
 897                 /* What should we make now? The advertisement
 898                    is invalid, but ndisc specs say nothing
 899                    about it. It could be misconfiguration, or
 900                    an smart proxy agent tries to help us :-)
 901
 902                    We should not print the error if NA has been
 903                    received from loopback - it is just our own
 904                    unsolicited advertisement.
 905                  */
 906                 if (skb->pkt_type != PACKET_LOOPBACK)
 907                         ND_PRINTK(1, warn,
 908                                   "NA: someone advertises our address %pI6 on %s!\n",
 909                                   &ifp->addr, ifp->idev->dev->name);
 910                 in6_ifa_put(ifp);
 911                 return;
 912         }
 913         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
 914
 915         if (neigh) {
 916                 u8 old_flags = neigh->flags;
 917                 struct net *net = dev_net(dev);
 918
 919                 if (neigh->nud_state & NUD_FAILED)
 920                         goto out;
 921
 922                 /*
 923                  * Don't update the neighbor cache entry on a proxy NA from
 924                  * ourselves because either the proxied node is off link or it
 925                  * has already sent a NA to us.
 926                  */
 927                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
 928                     net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
 929                     pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
 930                         /* XXX: idev->cnf.proxy_ndp */
 931                         goto out;
 932                 }
 933
 934                 neigh_update(neigh, lladdr,
 935                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
 936                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
 937                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
 938                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
 939                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
 940
 941                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
 942                         /*
 943                          * Change: router to host
 944                          */
 945                         struct rt6_info *rt;
 946                         rt = rt6_get_dflt_router(saddr, dev);
 947                         if (rt)
 948                                 ip6_del_rt(rt);
 949                 }
 950
 951 out:
 952                 neigh_release(neigh);
 953         }
 954 }
 955
 956 static void ndisc_recv_rs(struct sk_buff *skb)
 957 {
 958         struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
 959         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
 960         struct neighbour *neigh;
 961         struct inet6_dev *idev;
 962         const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 963         struct ndisc_options ndopts;
 964         u8 *lladdr = NULL;
 965
 966         if (skb->len < sizeof(*rs_msg))
 967                 return;
 968
 969         idev = __in6_dev_get(skb->dev);
 970         if (!idev) {
 971                 ND_PRINTK(1, err, "RS: can't find in6 device\n");
 972                 return;
 973         }
 974
 975         /* Don't accept RS if we're not in router mode */
 976         if (!idev->cnf.forwarding)
 977                 goto out;
 978
 979         /*
 980          * Don't update NCE if src = ::;
 981          * this implies that the source node has no ip address assigned yet.
 982          */
 983         if (ipv6_addr_any(saddr))
 984                 goto out;
 985
 986         /* Parse ND options */
 987         if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
 988                 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
 989                 goto out;
 990         }
 991
 992         if (ndopts.nd_opts_src_lladdr) {
 993                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
 994                                              skb->dev);
 995                 if (!lladdr)
 996                         goto out;
 997         }
 998
 999         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1000         if (neigh) {
1001                 neigh_update(neigh, lladdr, NUD_STALE,
1002                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1003                              NEIGH_UPDATE_F_OVERRIDE|
1004                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1005                 neigh_release(neigh);
1006         }
1007 out:
1008         return;
1009 }
1010
1011 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1012 {
1013         struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1014         struct sk_buff *skb;
1015         struct nlmsghdr *nlh;
1016         struct nduseroptmsg *ndmsg;
1017         struct net *net = dev_net(ra->dev);
1018         int err;
1019         int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1020                                     + (opt->nd_opt_len << 3));
1021         size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1022
1023         skb = nlmsg_new(msg_size, GFP_ATOMIC);
1024         if (skb == NULL) {
1025                 err = -ENOBUFS;
1026                 goto errout;
1027         }
1028
1029         nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1030         if (nlh == NULL) {
1031                 goto nla_put_failure;
1032         }
1033
1034         ndmsg = nlmsg_data(nlh);
1035         ndmsg->nduseropt_family = AF_INET6;
1036         ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1037         ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1038         ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1039         ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1040
1041         memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1042
1043         if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1044                     &ipv6_hdr(ra)->saddr))
1045                 goto nla_put_failure;
1046         nlmsg_end(skb, nlh);
1047
1048         rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1049         return;
1050
1051 nla_put_failure:
1052         nlmsg_free(skb);
1053         err = -EMSGSIZE;
1054 errout:
1055         rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1056 }
1057
1058 static void ndisc_router_discovery(struct sk_buff *skb)
1059 {
1060         struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1061         struct neighbour *neigh = NULL;
1062         struct inet6_dev *in6_dev;
1063         struct rt6_info *rt = NULL;
1064         int lifetime;
1065         struct ndisc_options ndopts;
1066         int optlen;
1067         unsigned int pref = 0;
1068
1069         __u8 * opt = (__u8 *)(ra_msg + 1);
1070
1071         optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1072                 sizeof(struct ra_msg);
1073
1074         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1075                 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1076                 return;
1077         }
1078         if (optlen < 0) {
1079                 ND_PRINTK(2, warn, "RA: packet too short\n");
1080                 return;
1081         }
1082
1083 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1084         if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1085                 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1086                 return;
1087         }
1088 #endif
1089
1090         /*
1091          *      set the RA_RECV flag in the interface
1092          */
1093
1094         in6_dev = __in6_dev_get(skb->dev);
1095         if (in6_dev == NULL) {
1096                 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1097                           skb->dev->name);
1098                 return;
1099         }
1100
1101         if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1102                 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1103                 return;
1104         }
1105
1106         if (!ipv6_accept_ra(in6_dev))
1107                 goto skip_linkparms;
1108
1109 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1110         /* skip link-specific parameters from interior routers */
1111         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1112                 goto skip_linkparms;
1113 #endif
1114
1115         if (in6_dev->if_flags & IF_RS_SENT) {
1116                 /*
1117                  *      flag that an RA was received after an RS was sent
1118                  *      out on this interface.
1119                  */
1120                 in6_dev->if_flags |= IF_RA_RCVD;
1121         }
1122
1123         /*
1124          * Remember the managed/otherconf flags from most recently
1125          * received RA message (RFC 2462) -- yoshfuji
1126          */
1127         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1128                                 IF_RA_OTHERCONF)) |
1129                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1130                                         IF_RA_MANAGED : 0) |
1131                                 (ra_msg->icmph.icmp6_addrconf_other ?
1132                                         IF_RA_OTHERCONF : 0);
1133
1134         if (!in6_dev->cnf.accept_ra_defrtr)
1135                 goto skip_defrtr;
1136
1137         if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1138                 goto skip_defrtr;
1139
1140         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1141
1142 #ifdef CONFIG_IPV6_ROUTER_PREF
1143         pref = ra_msg->icmph.icmp6_router_pref;
1144         /* 10b is handled as if it were 00b (medium) */
1145         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1146             !in6_dev->cnf.accept_ra_rtr_pref)
1147                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1148 #endif
1149
1150         rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1151
1152         if (rt) {
1153                 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1154                 if (!neigh) {
1155                         ND_PRINTK(0, err,
1156                                   "RA: %s got default router without neighbour\n",
1157                                   __func__);
1158                         ip6_rt_put(rt);
1159                         return;
1160                 }
1161         }
1162         if (rt && lifetime == 0) {
1163                 ip6_del_rt(rt);
1164                 rt = NULL;
1165         }
1166
1167         if (rt == NULL && lifetime) {
1168                 ND_PRINTK(3, dbg, "RA: adding default router\n");
1169
1170                 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1171                 if (rt == NULL) {
1172                         ND_PRINTK(0, err,
1173                                   "RA: %s failed to add default route\n",
1174                                   __func__);
1175                         return;
1176                 }
1177
1178                 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1179                 if (neigh == NULL) {
1180                         ND_PRINTK(0, err,
1181                                   "RA: %s got default router without neighbour\n",
1182                                   __func__);
1183                         ip6_rt_put(rt);
1184                         return;
1185                 }
1186                 neigh->flags |= NTF_ROUTER;
1187         } else if (rt) {
1188                 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1189         }
1190
1191         if (rt)
1192                 rt6_set_expires(rt, jiffies + (HZ * lifetime));
1193         if (ra_msg->icmph.icmp6_hop_limit) {
1194                 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1195                 if (rt)
1196                         dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1197                                        ra_msg->icmph.icmp6_hop_limit);
1198         }
1199
1200 skip_defrtr:
1201
1202         /*
1203          *      Update Reachable Time and Retrans Timer
1204          */
1205
1206         if (in6_dev->nd_parms) {
1207                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1208
1209                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1210                         rtime = (rtime*HZ)/1000;
1211                         if (rtime < HZ/10)
1212                                 rtime = HZ/10;
1213                         in6_dev->nd_parms->retrans_time = rtime;
1214                         in6_dev->tstamp = jiffies;
1215                         inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1216                 }
1217
1218                 rtime = ntohl(ra_msg->reachable_time);
1219                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1220                         rtime = (rtime*HZ)/1000;
1221
1222                         if (rtime < HZ/10)
1223                                 rtime = HZ/10;
1224
1225                         if (rtime != in6_dev->nd_parms->base_reachable_time) {
1226                                 in6_dev->nd_parms->base_reachable_time = rtime;
1227                                 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1228                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1229                                 in6_dev->tstamp = jiffies;
1230                                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1231                         }
1232                 }
1233         }
1234
1235 skip_linkparms:
1236
1237         /*
1238          *      Process options.
1239          */
1240
1241         if (!neigh)
1242                 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1243                                        skb->dev, 1);
1244         if (neigh) {
1245                 u8 *lladdr = NULL;
1246                 if (ndopts.nd_opts_src_lladdr) {
1247                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1248                                                      skb->dev);
1249                         if (!lladdr) {
1250                                 ND_PRINTK(2, warn,
1251                                           "RA: invalid link-layer address length\n");
1252                                 goto out;
1253                         }
1254                 }
1255                 neigh_update(neigh, lladdr, NUD_STALE,
1256                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1257                              NEIGH_UPDATE_F_OVERRIDE|
1258                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1259                              NEIGH_UPDATE_F_ISROUTER);
1260         }
1261
1262         if (!ipv6_accept_ra(in6_dev))
1263                 goto out;
1264
1265 #ifdef CONFIG_IPV6_ROUTE_INFO
1266         if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1267                 goto skip_routeinfo;
1268
1269         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1270                 struct nd_opt_hdr *p;
1271                 for (p = ndopts.nd_opts_ri;
1272                      p;
1273                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1274                         struct route_info *ri = (struct route_info *)p;
1275 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1276                         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1277                             ri->prefix_len == 0)
1278                                 continue;
1279 #endif
1280                         if (ri->prefix_len == 0 &&
1281                             !in6_dev->cnf.accept_ra_defrtr)
1282                                 continue;
1283                         if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1284                                 continue;
1285                         rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1286                                       &ipv6_hdr(skb)->saddr);
1287                 }
1288         }
1289
1290 skip_routeinfo:
1291 #endif
1292
1293 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1294         /* skip link-specific ndopts from interior routers */
1295         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1296                 goto out;
1297 #endif
1298
1299         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1300                 struct nd_opt_hdr *p;
1301                 for (p = ndopts.nd_opts_pi;
1302                      p;
1303                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1304                         addrconf_prefix_rcv(skb->dev, (u8 *)p,
1305                                             (p->nd_opt_len) << 3,
1306                                             ndopts.nd_opts_src_lladdr != NULL);
1307                 }
1308         }
1309
1310         if (ndopts.nd_opts_mtu) {
1311                 __be32 n;
1312                 u32 mtu;
1313
1314                 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1315                 mtu = ntohl(n);
1316
1317                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1318                         ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1319                 } else if (in6_dev->cnf.mtu6 != mtu) {
1320                         in6_dev->cnf.mtu6 = mtu;
1321
1322                         if (rt)
1323                                 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1324
1325                         rt6_mtu_change(skb->dev, mtu);
1326                 }
1327         }
1328
1329         if (ndopts.nd_useropts) {
1330                 struct nd_opt_hdr *p;
1331                 for (p = ndopts.nd_useropts;
1332                      p;
1333                      p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1334                         ndisc_ra_useropt(skb, p);
1335                 }
1336         }
1337
1338         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1339                 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1340         }
1341 out:
1342         ip6_rt_put(rt);
1343         if (neigh)
1344                 neigh_release(neigh);
1345 }
1346
1347 static void ndisc_redirect_rcv(struct sk_buff *skb)
1348 {
1349         u8 *hdr;
1350         struct ndisc_options ndopts;
1351         struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1352         u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1353                                     offsetof(struct rd_msg, opt));
1354
1355 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1356         switch (skb->ndisc_nodetype) {
1357         case NDISC_NODETYPE_HOST:
1358         case NDISC_NODETYPE_NODEFAULT:
1359                 ND_PRINTK(2, warn,
1360                           "Redirect: from host or unauthorized router\n");
1361                 return;
1362         }
1363 #endif
1364
1365         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1366                 ND_PRINTK(2, warn,
1367                           "Redirect: source address is not link-local\n");
1368                 return;
1369         }
1370
1371         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts))
1372                 return;
1373
1374         if (!ndopts.nd_opts_rh) {
1375                 ip6_redirect_no_header(skb, dev_net(skb->dev),
1376                                         skb->dev->ifindex, 0);
1377                 return;
1378         }
1379
1380         hdr = (u8 *)ndopts.nd_opts_rh;
1381         hdr += 8;
1382         if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1383                 return;
1384
1385         icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1386 }
1387
1388 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1389                                            struct sk_buff *orig_skb,
1390                                            int rd_len)
1391 {
1392         u8 *opt = skb_put(skb, rd_len);
1393
1394         memset(opt, 0, 8);
1395         *(opt++) = ND_OPT_REDIRECT_HDR;
1396         *(opt++) = (rd_len >> 3);
1397         opt += 6;
1398
1399         memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8);
1400 }
1401
1402 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1403 {
1404         struct net_device *dev = skb->dev;
1405         struct net *net = dev_net(dev);
1406         struct sock *sk = net->ipv6.ndisc_sk;
1407         int optlen = 0;
1408         struct inet_peer *peer;
1409         struct sk_buff *buff;
1410         struct rd_msg *msg;
1411         struct in6_addr saddr_buf;
1412         struct rt6_info *rt;
1413         struct dst_entry *dst;
1414         struct flowi6 fl6;
1415         int rd_len;
1416         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1417         bool ret;
1418
1419         if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1420                 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1421                           dev->name);
1422                 return;
1423         }
1424
1425         if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1426             ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1427                 ND_PRINTK(2, warn,
1428                           "Redirect: target address is not link-local unicast\n");
1429                 return;
1430         }
1431
1432         icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1433                          &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1434
1435         dst = ip6_route_output(net, NULL, &fl6);
1436         if (dst->error) {
1437                 dst_release(dst);
1438                 return;
1439         }
1440         dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1441         if (IS_ERR(dst))
1442                 return;
1443
1444         rt = (struct rt6_info *) dst;
1445
1446         if (rt->rt6i_flags & RTF_GATEWAY) {
1447                 ND_PRINTK(2, warn,
1448                           "Redirect: destination is not a neighbour\n");
1449                 goto release;
1450         }
1451         peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
1452         ret = inet_peer_xrlim_allow(peer, 1*HZ);
1453         if (peer)
1454                 inet_putpeer(peer);
1455         if (!ret)
1456                 goto release;
1457
1458         if (dev->addr_len) {
1459                 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1460                 if (!neigh) {
1461                         ND_PRINTK(2, warn,
1462                                   "Redirect: no neigh for target address\n");
1463                         goto release;
1464                 }
1465
1466                 read_lock_bh(&neigh->lock);
1467                 if (neigh->nud_state & NUD_VALID) {
1468                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1469                         read_unlock_bh(&neigh->lock);
1470                         ha = ha_buf;
1471                         optlen += ndisc_opt_addr_space(dev);
1472                 } else
1473                         read_unlock_bh(&neigh->lock);
1474
1475                 neigh_release(neigh);
1476         }
1477
1478         rd_len = min_t(unsigned int,
1479                        IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1480                        skb->len + 8);
1481         rd_len &= ~0x7;
1482         optlen += rd_len;
1483
1484         buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1485         if (!buff)
1486                 goto release;
1487
1488         msg = (struct rd_msg *)skb_put(buff, sizeof(*msg));
1489         *msg = (struct rd_msg) {
1490                 .icmph = {
1491                         .icmp6_type = NDISC_REDIRECT,
1492                 },
1493                 .target = *target,
1494                 .dest = ipv6_hdr(skb)->daddr,
1495         };
1496
1497         /*
1498          *      include target_address option
1499          */
1500
1501         if (ha)
1502                 ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha);
1503
1504         /*
1505          *      build redirect option and copy skb over to the new packet.
1506          */
1507
1508         if (rd_len)
1509                 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1510
1511         skb_dst_set(buff, dst);
1512         ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1513         return;
1514
1515 release:
1516         dst_release(dst);
1517 }
1518
1519 static void pndisc_redo(struct sk_buff *skb)
1520 {
1521         ndisc_recv_ns(skb);
1522         kfree_skb(skb);
1523 }
1524
1525 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1526 {
1527         struct inet6_dev *idev = __in6_dev_get(skb->dev);
1528
1529         if (!idev)
1530                 return true;
1531         if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1532             idev->cnf.suppress_frag_ndisc) {
1533                 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1534                 return true;
1535         }
1536         return false;
1537 }
1538
1539 int ndisc_rcv(struct sk_buff *skb)
1540 {
1541         struct nd_msg *msg;
1542
1543         if (ndisc_suppress_frag_ndisc(skb))
1544                 return 0;
1545
1546         if (skb_linearize(skb))
1547                 return 0;
1548
1549         msg = (struct nd_msg *)skb_transport_header(skb);
1550
1551         __skb_push(skb, skb->data - skb_transport_header(skb));
1552
1553         if (ipv6_hdr(skb)->hop_limit != 255) {
1554                 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1555                           ipv6_hdr(skb)->hop_limit);
1556                 return 0;
1557         }
1558
1559         if (msg->icmph.icmp6_code != 0) {
1560                 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1561                           msg->icmph.icmp6_code);
1562                 return 0;
1563         }
1564
1565         memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1566
1567         switch (msg->icmph.icmp6_type) {
1568         case NDISC_NEIGHBOUR_SOLICITATION:
1569                 ndisc_recv_ns(skb);
1570                 break;
1571
1572         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1573                 ndisc_recv_na(skb);
1574                 break;
1575
1576         case NDISC_ROUTER_SOLICITATION:
1577                 ndisc_recv_rs(skb);
1578                 break;
1579
1580         case NDISC_ROUTER_ADVERTISEMENT:
1581                 ndisc_router_discovery(skb);
1582                 break;
1583
1584         case NDISC_REDIRECT:
1585                 ndisc_redirect_rcv(skb);
1586                 break;
1587         }
1588
1589         return 0;
1590 }
1591
1592 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1593 {
1594         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1595         struct net *net = dev_net(dev);
1596         struct inet6_dev *idev;
1597
1598         switch (event) {
1599         case NETDEV_CHANGEADDR:
1600                 neigh_changeaddr(&nd_tbl, dev);
1601                 fib6_run_gc(0, net, false);
1602                 idev = in6_dev_get(dev);
1603                 if (!idev)
1604                         break;
1605                 if (idev->cnf.ndisc_notify)
1606                         ndisc_send_unsol_na(dev);
1607                 in6_dev_put(idev);
1608                 break;
1609         case NETDEV_DOWN:
1610                 neigh_ifdown(&nd_tbl, dev);
1611                 fib6_run_gc(0, net, false);
1612                 break;
1613         case NETDEV_NOTIFY_PEERS:
1614                 ndisc_send_unsol_na(dev);
1615                 break;
1616         default:
1617                 break;
1618         }
1619
1620         return NOTIFY_DONE;
1621 }
1622
1623 static struct notifier_block ndisc_netdev_notifier = {
1624         .notifier_call = ndisc_netdev_event,
1625 };
1626
1627 #ifdef CONFIG_SYSCTL
1628 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1629                                          const char *func, const char *dev_name)
1630 {
1631         static char warncomm[TASK_COMM_LEN];
1632         static int warned;
1633         if (strcmp(warncomm, current->comm) && warned < 5) {
1634                 strcpy(warncomm, current->comm);
1635                 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1636                         warncomm, func,
1637                         dev_name, ctl->procname,
1638                         dev_name, ctl->procname);
1639                 warned++;
1640         }
1641 }
1642
1643 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1644 {
1645         struct net_device *dev = ctl->extra1;
1646         struct inet6_dev *idev;
1647         int ret;
1648
1649         if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1650             (strcmp(ctl->procname, "base_reachable_time") == 0))
1651                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1652
1653         if (strcmp(ctl->procname, "retrans_time") == 0)
1654                 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1655
1656         else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1657                 ret = proc_dointvec_jiffies(ctl, write,
1658                                             buffer, lenp, ppos);
1659
1660         else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1661                  (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1662                 ret = proc_dointvec_ms_jiffies(ctl, write,
1663                                                buffer, lenp, ppos);
1664         else
1665                 ret = -1;
1666
1667         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1668                 if (ctl->data == &idev->nd_parms->base_reachable_time)
1669                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1670                 idev->tstamp = jiffies;
1671                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1672                 in6_dev_put(idev);
1673         }
1674         return ret;
1675 }
1676
1677
1678 #endif
1679
1680 static int __net_init ndisc_net_init(struct net *net)
1681 {
1682         struct ipv6_pinfo *np;
1683         struct sock *sk;
1684         int err;
1685
1686         err = inet_ctl_sock_create(&sk, PF_INET6,
1687                                    SOCK_RAW, IPPROTO_ICMPV6, net);
1688         if (err < 0) {
1689                 ND_PRINTK(0, err,
1690                           "NDISC: Failed to initialize the control socket (err %d)\n",
1691                           err);
1692                 return err;
1693         }
1694
1695         net->ipv6.ndisc_sk = sk;
1696
1697         np = inet6_sk(sk);
1698         np->hop_limit = 255;
1699         /* Do not loopback ndisc messages */
1700         np->mc_loop = 0;
1701
1702         return 0;
1703 }
1704
1705 static void __net_exit ndisc_net_exit(struct net *net)
1706 {
1707         inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1708 }
1709
1710 static struct pernet_operations ndisc_net_ops = {
1711         .init = ndisc_net_init,
1712         .exit = ndisc_net_exit,
1713 };
1714
1715 int __init ndisc_init(void)
1716 {
1717         int err;
1718
1719         err = register_pernet_subsys(&ndisc_net_ops);
1720         if (err)
1721                 return err;
1722         /*
1723          * Initialize the neighbour table
1724          */
1725         neigh_table_init(&nd_tbl);
1726
1727 #ifdef CONFIG_SYSCTL
1728         err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6",
1729                                     &ndisc_ifinfo_sysctl_change);
1730         if (err)
1731                 goto out_unregister_pernet;
1732 out:
1733 #endif
1734         return err;
1735
1736 #ifdef CONFIG_SYSCTL
1737 out_unregister_pernet:
1738         unregister_pernet_subsys(&ndisc_net_ops);
1739         goto out;
1740 #endif
1741 }
1742
1743 int __init ndisc_late_init(void)
1744 {
1745         return register_netdevice_notifier(&ndisc_netdev_notifier);
1746 }
1747
1748 void ndisc_late_cleanup(void)
1749 {
1750         unregister_netdevice_notifier(&ndisc_netdev_notifier);
1751 }
1752
1753 void ndisc_cleanup(void)
1754 {
1755 #ifdef CONFIG_SYSCTL
1756         neigh_sysctl_unregister(&nd_tbl.parms);
1757 #endif
1758         neigh_table_clear(&nd_tbl);
1759         unregister_pernet_subsys(&ndisc_net_ops);
1760 }