net/ipv6/ndisc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Neighbour Discovery for IPv6
   4  *      Linux INET6 implementation
   5  *
   6  *      Authors:
   7  *      Pedro Roque             <[email protected]>
   8  *      Mike Shaver             <[email protected]>
   9  */
  10
  11 /*
  12  *      Changes:
  13  *
  14  *      Alexey I. Froloff               :       RFC6106 (DNSSL) support
  15  *      Pierre Ynard                    :       export userland ND options
  16  *                                              through netlink (RDNSS support)
  17  *      Lars Fenneberg                  :       fixed MTU setting on receipt
  18  *                                              of an RA.
  19  *      Janos Farkas                    :       kmalloc failure checks
  20  *      Alexey Kuznetsov                :       state machine reworked
  21  *                                              and moved to net/core.
  22  *      Pekka Savola                    :       RFC2461 validation
  23  *      YOSHIFUJI Hideaki @USAGI        :       Verify ND options properly
  24  */
  25
  26 #define pr_fmt(fmt) "ICMPv6: " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/types.h>
  31 #include <linux/socket.h>
  32 #include <linux/sockios.h>
  33 #include <linux/sched.h>
  34 #include <linux/net.h>
  35 #include <linux/in6.h>
  36 #include <linux/route.h>
  37 #include <linux/init.h>
  38 #include <linux/rcupdate.h>
  39 #include <linux/slab.h>
  40 #ifdef CONFIG_SYSCTL
  41 #include <linux/sysctl.h>
  42 #endif
  43
  44 #include <linux/if_addr.h>
  45 #include <linux/if_ether.h>
  46 #include <linux/if_arp.h>
  47 #include <linux/ipv6.h>
  48 #include <linux/icmpv6.h>
  49 #include <linux/jhash.h>
  50
  51 #include <net/sock.h>
  52 #include <net/snmp.h>
  53
  54 #include <net/ipv6.h>
  55 #include <net/protocol.h>
  56 #include <net/ndisc.h>
  57 #include <net/ip6_route.h>
  58 #include <net/addrconf.h>
  59 #include <net/icmp.h>
  60
  61 #include <net/netlink.h>
  62 #include <linux/rtnetlink.h>
  63
  64 #include <net/flow.h>
  65 #include <net/ip6_checksum.h>
  66 #include <net/inet_common.h>
  67 #include <linux/proc_fs.h>
  68
  69 #include <linux/netfilter.h>
  70 #include <linux/netfilter_ipv6.h>
  71
  72 static u32 ndisc_hash(const void *pkey,
  73                       const struct net_device *dev,
  74                       __u32 *hash_rnd);
  75 static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
  76 static bool ndisc_allow_add(const struct net_device *dev,
  77                             struct netlink_ext_ack *extack);
  78 static int ndisc_constructor(struct neighbour *neigh);
  79 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
  80 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
  81 static int pndisc_constructor(struct pneigh_entry *n);
  82 static void pndisc_destructor(struct pneigh_entry *n);
  83 static void pndisc_redo(struct sk_buff *skb);
  84 static int ndisc_is_multicast(const void *pkey);
  85
  86 static const struct neigh_ops ndisc_generic_ops = {
  87         .family =               AF_INET6,
  88         .solicit =              ndisc_solicit,
  89         .error_report =         ndisc_error_report,
  90         .output =               neigh_resolve_output,
  91         .connected_output =     neigh_connected_output,
  92 };
  93
  94 static const struct neigh_ops ndisc_hh_ops = {
  95         .family =               AF_INET6,
  96         .solicit =              ndisc_solicit,
  97         .error_report =         ndisc_error_report,
  98         .output =               neigh_resolve_output,
  99         .connected_output =     neigh_resolve_output,
 100 };
 101
 102
 103 static const struct neigh_ops ndisc_direct_ops = {
 104         .family =               AF_INET6,
 105         .output =               neigh_direct_output,
 106         .connected_output =     neigh_direct_output,
 107 };
 108
 109 struct neigh_table nd_tbl = {
 110         .family =       AF_INET6,
 111         .key_len =      sizeof(struct in6_addr),
 112         .protocol =     cpu_to_be16(ETH_P_IPV6),
 113         .hash =         ndisc_hash,
 114         .key_eq =       ndisc_key_eq,
 115         .constructor =  ndisc_constructor,
 116         .pconstructor = pndisc_constructor,
 117         .pdestructor =  pndisc_destructor,
 118         .proxy_redo =   pndisc_redo,
 119         .is_multicast = ndisc_is_multicast,
 120         .allow_add  =   ndisc_allow_add,
 121         .id =           "ndisc_cache",
 122         .parms = {
 123                 .tbl                    = &nd_tbl,
 124                 .reachable_time         = ND_REACHABLE_TIME,
 125                 .data = {
 126                         [NEIGH_VAR_MCAST_PROBES] = 3,
 127                         [NEIGH_VAR_UCAST_PROBES] = 3,
 128                         [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
 129                         [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
 130                         [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
 131                         [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 132                         [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
 133                         [NEIGH_VAR_PROXY_QLEN] = 64,
 134                         [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
 135                         [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
 136                 },
 137         },
 138         .gc_interval =    30 * HZ,
 139         .gc_thresh1 =    128,
 140         .gc_thresh2 =    512,
 141         .gc_thresh3 =   1024,
 142 };
 143 EXPORT_SYMBOL_GPL(nd_tbl);
 144
 145 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 146                               int data_len, int pad)
 147 {
 148         int space = __ndisc_opt_addr_space(data_len, pad);
 149         u8 *opt = skb_put(skb, space);
 150
 151         opt[0] = type;
 152         opt[1] = space>>3;
 153
 154         memset(opt + 2, 0, pad);
 155         opt   += pad;
 156         space -= pad;
 157
 158         memcpy(opt+2, data, data_len);
 159         data_len += 2;
 160         opt += data_len;
 161         space -= data_len;
 162         if (space > 0)
 163                 memset(opt, 0, space);
 164 }
 165 EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
 166
 167 static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
 168                                           void *data, u8 icmp6_type)
 169 {
 170         __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
 171                                  ndisc_addr_option_pad(skb->dev->type));
 172         ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
 173 }
 174
 175 static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
 176                                                    void *ha,
 177                                                    const u8 *ops_data)
 178 {
 179         ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
 180         ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
 181 }
 182
 183 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 184                                             struct nd_opt_hdr *end)
 185 {
 186         int type;
 187         if (!cur || !end || cur >= end)
 188                 return NULL;
 189         type = cur->nd_opt_type;
 190         do {
 191                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
 192         } while (cur < end && cur->nd_opt_type != type);
 193         return cur <= end && cur->nd_opt_type == type ? cur : NULL;
 194 }
 195
 196 static inline int ndisc_is_useropt(const struct net_device *dev,
 197                                    struct nd_opt_hdr *opt)
 198 {
 199         return opt->nd_opt_type == ND_OPT_RDNSS ||
 200                 opt->nd_opt_type == ND_OPT_DNSSL ||
 201                 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
 202                 opt->nd_opt_type == ND_OPT_PREF64 ||
 203                 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
 204 }
 205
 206 static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
 207                                              struct nd_opt_hdr *cur,
 208                                              struct nd_opt_hdr *end)
 209 {
 210         if (!cur || !end || cur >= end)
 211                 return NULL;
 212         do {
 213                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
 214         } while (cur < end && !ndisc_is_useropt(dev, cur));
 215         return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
 216 }
 217
 218 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 219                                           u8 *opt, int opt_len,
 220                                           struct ndisc_options *ndopts)
 221 {
 222         struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 223
 224         if (!nd_opt || opt_len < 0 || !ndopts)
 225                 return NULL;
 226         memset(ndopts, 0, sizeof(*ndopts));
 227         while (opt_len) {
 228                 int l;
 229                 if (opt_len < sizeof(struct nd_opt_hdr))
 230                         return NULL;
 231                 l = nd_opt->nd_opt_len << 3;
 232                 if (opt_len < l || l == 0)
 233                         return NULL;
 234                 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
 235                         goto next_opt;
 236                 switch (nd_opt->nd_opt_type) {
 237                 case ND_OPT_SOURCE_LL_ADDR:
 238                 case ND_OPT_TARGET_LL_ADDR:
 239                 case ND_OPT_MTU:
 240                 case ND_OPT_NONCE:
 241                 case ND_OPT_REDIRECT_HDR:
 242                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 243                                 ND_PRINTK(2, warn,
 244                                           "%s: duplicated ND6 option found: type=%d\n",
 245                                           __func__, nd_opt->nd_opt_type);
 246                         } else {
 247                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 248                         }
 249                         break;
 250                 case ND_OPT_PREFIX_INFO:
 251                         ndopts->nd_opts_pi_end = nd_opt;
 252                         if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 253                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 254                         break;
 255 #ifdef CONFIG_IPV6_ROUTE_INFO
 256                 case ND_OPT_ROUTE_INFO:
 257                         ndopts->nd_opts_ri_end = nd_opt;
 258                         if (!ndopts->nd_opts_ri)
 259                                 ndopts->nd_opts_ri = nd_opt;
 260                         break;
 261 #endif
 262                 default:
 263                         if (ndisc_is_useropt(dev, nd_opt)) {
 264                                 ndopts->nd_useropts_end = nd_opt;
 265                                 if (!ndopts->nd_useropts)
 266                                         ndopts->nd_useropts = nd_opt;
 267                         } else {
 268                                 /*
 269                                  * Unknown options must be silently ignored,
 270                                  * to accommodate future extension to the
 271                                  * protocol.
 272                                  */
 273                                 ND_PRINTK(2, notice,
 274                                           "%s: ignored unsupported option; type=%d, len=%d\n",
 275                                           __func__,
 276                                           nd_opt->nd_opt_type,
 277                                           nd_opt->nd_opt_len);
 278                         }
 279                 }
 280 next_opt:
 281                 opt_len -= l;
 282                 nd_opt = ((void *)nd_opt) + l;
 283         }
 284         return ndopts;
 285 }
 286
 287 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 288 {
 289         switch (dev->type) {
 290         case ARPHRD_ETHER:
 291         case ARPHRD_IEEE802:    /* Not sure. Check it later. --ANK */
 292         case ARPHRD_FDDI:
 293                 ipv6_eth_mc_map(addr, buf);
 294                 return 0;
 295         case ARPHRD_ARCNET:
 296                 ipv6_arcnet_mc_map(addr, buf);
 297                 return 0;
 298         case ARPHRD_INFINIBAND:
 299                 ipv6_ib_mc_map(addr, dev->broadcast, buf);
 300                 return 0;
 301         case ARPHRD_IPGRE:
 302                 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
 303         default:
 304                 if (dir) {
 305                         memcpy(buf, dev->broadcast, dev->addr_len);
 306                         return 0;
 307                 }
 308         }
 309         return -EINVAL;
 310 }
 311 EXPORT_SYMBOL(ndisc_mc_map);
 312
 313 static u32 ndisc_hash(const void *pkey,
 314                       const struct net_device *dev,
 315                       __u32 *hash_rnd)
 316 {
 317         return ndisc_hashfn(pkey, dev, hash_rnd);
 318 }
 319
 320 static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
 321 {
 322         return neigh_key_eq128(n, pkey);
 323 }
 324
 325 static int ndisc_constructor(struct neighbour *neigh)
 326 {
 327         struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
 328         struct net_device *dev = neigh->dev;
 329         struct inet6_dev *in6_dev;
 330         struct neigh_parms *parms;
 331         bool is_multicast = ipv6_addr_is_multicast(addr);
 332
 333         in6_dev = in6_dev_get(dev);
 334         if (!in6_dev) {
 335                 return -EINVAL;
 336         }
 337
 338         parms = in6_dev->nd_parms;
 339         __neigh_parms_put(neigh->parms);
 340         neigh->parms = neigh_parms_clone(parms);
 341
 342         neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 343         if (!dev->header_ops) {
 344                 neigh->nud_state = NUD_NOARP;
 345                 neigh->ops = &ndisc_direct_ops;
 346                 neigh->output = neigh_direct_output;
 347         } else {
 348                 if (is_multicast) {
 349                         neigh->nud_state = NUD_NOARP;
 350                         ndisc_mc_map(addr, neigh->ha, dev, 1);
 351                 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 352                         neigh->nud_state = NUD_NOARP;
 353                         memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 354                         if (dev->flags&IFF_LOOPBACK)
 355                                 neigh->type = RTN_LOCAL;
 356                 } else if (dev->flags&IFF_POINTOPOINT) {
 357                         neigh->nud_state = NUD_NOARP;
 358                         memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 359                 }
 360                 if (dev->header_ops->cache)
 361                         neigh->ops = &ndisc_hh_ops;
 362                 else
 363                         neigh->ops = &ndisc_generic_ops;
 364                 if (neigh->nud_state&NUD_VALID)
 365                         neigh->output = neigh->ops->connected_output;
 366                 else
 367                         neigh->output = neigh->ops->output;
 368         }
 369         in6_dev_put(in6_dev);
 370         return 0;
 371 }
 372
 373 static int pndisc_constructor(struct pneigh_entry *n)
 374 {
 375         struct in6_addr *addr = (struct in6_addr *)&n->key;
 376         struct in6_addr maddr;
 377         struct net_device *dev = n->dev;
 378
 379         if (!dev || !__in6_dev_get(dev))
 380                 return -EINVAL;
 381         addrconf_addr_solict_mult(addr, &maddr);
 382         ipv6_dev_mc_inc(dev, &maddr);
 383         return 0;
 384 }
 385
 386 static void pndisc_destructor(struct pneigh_entry *n)
 387 {
 388         struct in6_addr *addr = (struct in6_addr *)&n->key;
 389         struct in6_addr maddr;
 390         struct net_device *dev = n->dev;
 391
 392         if (!dev || !__in6_dev_get(dev))
 393                 return;
 394         addrconf_addr_solict_mult(addr, &maddr);
 395         ipv6_dev_mc_dec(dev, &maddr);
 396 }
 397
 398 /* called with rtnl held */
 399 static bool ndisc_allow_add(const struct net_device *dev,
 400                             struct netlink_ext_ack *extack)
 401 {
 402         struct inet6_dev *idev = __in6_dev_get(dev);
 403
 404         if (!idev || idev->cnf.disable_ipv6) {
 405                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
 406                 return false;
 407         }
 408
 409         return true;
 410 }
 411
 412 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 413                                        int len)
 414 {
 415         int hlen = LL_RESERVED_SPACE(dev);
 416         int tlen = dev->needed_tailroom;
 417         struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
 418         struct sk_buff *skb;
 419
 420         skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
 421         if (!skb) {
 422                 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
 423                           __func__);
 424                 return NULL;
 425         }
 426
 427         skb->protocol = htons(ETH_P_IPV6);
 428         skb->dev = dev;
 429
 430         skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
 431         skb_reset_transport_header(skb);
 432
 433         /* Manually assign socket ownership as we avoid calling
 434          * sock_alloc_send_pskb() to bypass wmem buffer limits
 435          */
 436         skb_set_owner_w(skb, sk);
 437
 438         return skb;
 439 }
 440
 441 static void ip6_nd_hdr(struct sk_buff *skb,
 442                        const struct in6_addr *saddr,
 443                        const struct in6_addr *daddr,
 444                        int hop_limit, int len)
 445 {
 446         struct ipv6hdr *hdr;
 447         struct inet6_dev *idev;
 448         unsigned tclass;
 449
 450         rcu_read_lock();
 451         idev = __in6_dev_get(skb->dev);
 452         tclass = idev ? idev->cnf.ndisc_tclass : 0;
 453         rcu_read_unlock();
 454
 455         skb_push(skb, sizeof(*hdr));
 456         skb_reset_network_header(skb);
 457         hdr = ipv6_hdr(skb);
 458
 459         ip6_flow_hdr(hdr, tclass, 0);
 460
 461         hdr->payload_len = htons(len);
 462         hdr->nexthdr = IPPROTO_ICMPV6;
 463         hdr->hop_limit = hop_limit;
 464
 465         hdr->saddr = *saddr;
 466         hdr->daddr = *daddr;
 467 }
 468
 469 static void ndisc_send_skb(struct sk_buff *skb,
 470                            const struct in6_addr *daddr,
 471                            const struct in6_addr *saddr)
 472 {
 473         struct dst_entry *dst = skb_dst(skb);
 474         struct net *net = dev_net(skb->dev);
 475         struct sock *sk = net->ipv6.ndisc_sk;
 476         struct inet6_dev *idev;
 477         int err;
 478         struct icmp6hdr *icmp6h = icmp6_hdr(skb);
 479         u8 type;
 480
 481         type = icmp6h->icmp6_type;
 482
 483         if (!dst) {
 484                 struct flowi6 fl6;
 485                 int oif = skb->dev->ifindex;
 486
 487                 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
 488                 dst = icmp6_dst_alloc(skb->dev, &fl6);
 489                 if (IS_ERR(dst)) {
 490                         kfree_skb(skb);
 491                         return;
 492                 }
 493
 494                 skb_dst_set(skb, dst);
 495         }
 496
 497         icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
 498                                               IPPROTO_ICMPV6,
 499                                               csum_partial(icmp6h,
 500                                                            skb->len, 0));
 501
 502         ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
 503
 504         rcu_read_lock();
 505         idev = __in6_dev_get(dst->dev);
 506         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
 507
 508         err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
 509                       net, sk, skb, NULL, dst->dev,
 510                       dst_output);
 511         if (!err) {
 512                 ICMP6MSGOUT_INC_STATS(net, idev, type);
 513                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 514         }
 515
 516         rcu_read_unlock();
 517 }
 518
 519 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 520                    const struct in6_addr *solicited_addr,
 521                    bool router, bool solicited, bool override, bool inc_opt)
 522 {
 523         struct sk_buff *skb;
 524         struct in6_addr tmpaddr;
 525         struct inet6_ifaddr *ifp;
 526         const struct in6_addr *src_addr;
 527         struct nd_msg *msg;
 528         int optlen = 0;
 529
 530         /* for anycast or proxy, solicited_addr != src_addr */
 531         ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 532         if (ifp) {
 533                 src_addr = solicited_addr;
 534                 if (ifp->flags & IFA_F_OPTIMISTIC)
 535                         override = false;
 536                 inc_opt |= ifp->idev->cnf.force_tllao;
 537                 in6_ifa_put(ifp);
 538         } else {
 539                 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 540                                        inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 541                                        &tmpaddr))
 542                         return;
 543                 src_addr = &tmpaddr;
 544         }
 545
 546         if (!dev->addr_len)
 547                 inc_opt = false;
 548         if (inc_opt)
 549                 optlen += ndisc_opt_addr_space(dev,
 550                                                NDISC_NEIGHBOUR_ADVERTISEMENT);
 551
 552         skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 553         if (!skb)
 554                 return;
 555
 556         msg = skb_put(skb, sizeof(*msg));
 557         *msg = (struct nd_msg) {
 558                 .icmph = {
 559                         .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 560                         .icmp6_router = router,
 561                         .icmp6_solicited = solicited,
 562                         .icmp6_override = override,
 563                 },
 564                 .target = *solicited_addr,
 565         };
 566
 567         if (inc_opt)
 568                 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
 569                                        dev->dev_addr,
 570                                        NDISC_NEIGHBOUR_ADVERTISEMENT);
 571
 572         ndisc_send_skb(skb, daddr, src_addr);
 573 }
 574
 575 static void ndisc_send_unsol_na(struct net_device *dev)
 576 {
 577         struct inet6_dev *idev;
 578         struct inet6_ifaddr *ifa;
 579
 580         idev = in6_dev_get(dev);
 581         if (!idev)
 582                 return;
 583
 584         read_lock_bh(&idev->lock);
 585         list_for_each_entry(ifa, &idev->addr_list, if_list) {
 586                 /* skip tentative addresses until dad completes */
 587                 if (ifa->flags & IFA_F_TENTATIVE &&
 588                     !(ifa->flags & IFA_F_OPTIMISTIC))
 589                         continue;
 590
 591                 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
 592                               /*router=*/ !!idev->cnf.forwarding,
 593                               /*solicited=*/ false, /*override=*/ true,
 594                               /*inc_opt=*/ true);
 595         }
 596         read_unlock_bh(&idev->lock);
 597
 598         in6_dev_put(idev);
 599 }
 600
 601 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 602                    const struct in6_addr *daddr, const struct in6_addr *saddr,
 603                    u64 nonce)
 604 {
 605         struct sk_buff *skb;
 606         struct in6_addr addr_buf;
 607         int inc_opt = dev->addr_len;
 608         int optlen = 0;
 609         struct nd_msg *msg;
 610
 611         if (!saddr) {
 612                 if (ipv6_get_lladdr(dev, &addr_buf,
 613                                    (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 614                         return;
 615                 saddr = &addr_buf;
 616         }
 617
 618         if (ipv6_addr_any(saddr))
 619                 inc_opt = false;
 620         if (inc_opt)
 621                 optlen += ndisc_opt_addr_space(dev,
 622                                                NDISC_NEIGHBOUR_SOLICITATION);
 623         if (nonce != 0)
 624                 optlen += 8;
 625
 626         skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 627         if (!skb)
 628                 return;
 629
 630         msg = skb_put(skb, sizeof(*msg));
 631         *msg = (struct nd_msg) {
 632                 .icmph = {
 633                         .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 634                 },
 635                 .target = *solicit,
 636         };
 637
 638         if (inc_opt)
 639                 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 640                                        dev->dev_addr,
 641                                        NDISC_NEIGHBOUR_SOLICITATION);
 642         if (nonce != 0) {
 643                 u8 *opt = skb_put(skb, 8);
 644
 645                 opt[0] = ND_OPT_NONCE;
 646                 opt[1] = 8 >> 3;
 647                 memcpy(opt + 2, &nonce, 6);
 648         }
 649
 650         ndisc_send_skb(skb, daddr, saddr);
 651 }
 652
 653 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 654                    const struct in6_addr *daddr)
 655 {
 656         struct sk_buff *skb;
 657         struct rs_msg *msg;
 658         int send_sllao = dev->addr_len;
 659         int optlen = 0;
 660
 661 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 662         /*
 663          * According to section 2.2 of RFC 4429, we must not
 664          * send router solicitations with a sllao from
 665          * optimistic addresses, but we may send the solicitation
 666          * if we don't include the sllao.  So here we check
 667          * if our address is optimistic, and if so, we
 668          * suppress the inclusion of the sllao.
 669          */
 670         if (send_sllao) {
 671                 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 672                                                            dev, 1);
 673                 if (ifp) {
 674                         if (ifp->flags & IFA_F_OPTIMISTIC)  {
 675                                 send_sllao = 0;
 676                         }
 677                         in6_ifa_put(ifp);
 678                 } else {
 679                         send_sllao = 0;
 680                 }
 681         }
 682 #endif
 683         if (send_sllao)
 684                 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
 685
 686         skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 687         if (!skb)
 688                 return;
 689
 690         msg = skb_put(skb, sizeof(*msg));
 691         *msg = (struct rs_msg) {
 692                 .icmph = {
 693                         .icmp6_type = NDISC_ROUTER_SOLICITATION,
 694                 },
 695         };
 696
 697         if (send_sllao)
 698                 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 699                                        dev->dev_addr,
 700                                        NDISC_ROUTER_SOLICITATION);
 701
 702         ndisc_send_skb(skb, daddr, saddr);
 703 }
 704
 705
 706 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 707 {
 708         /*
 709          *      "The sender MUST return an ICMP
 710          *       destination unreachable"
 711          */
 712         dst_link_failure(skb);
 713         kfree_skb(skb);
 714 }
 715
 716 /* Called with locked neigh: either read or both */
 717
 718 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 719 {
 720         struct in6_addr *saddr = NULL;
 721         struct in6_addr mcaddr;
 722         struct net_device *dev = neigh->dev;
 723         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 724         int probes = atomic_read(&neigh->probes);
 725
 726         if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
 727                                            dev, false, 1,
 728                                            IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
 729                 saddr = &ipv6_hdr(skb)->saddr;
 730         probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
 731         if (probes < 0) {
 732                 if (!(neigh->nud_state & NUD_VALID)) {
 733                         ND_PRINTK(1, dbg,
 734                                   "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
 735                                   __func__, target);
 736                 }
 737                 ndisc_send_ns(dev, target, target, saddr, 0);
 738         } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
 739                 neigh_app_ns(neigh);
 740         } else {
 741                 addrconf_addr_solict_mult(target, &mcaddr);
 742                 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
 743         }
 744 }
 745
 746 static int pndisc_is_router(const void *pkey,
 747                             struct net_device *dev)
 748 {
 749         struct pneigh_entry *n;
 750         int ret = -1;
 751
 752         read_lock_bh(&nd_tbl.lock);
 753         n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 754         if (n)
 755                 ret = !!(n->flags & NTF_ROUTER);
 756         read_unlock_bh(&nd_tbl.lock);
 757
 758         return ret;
 759 }
 760
 761 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 762                   const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 763                   struct ndisc_options *ndopts)
 764 {
 765         neigh_update(neigh, lladdr, new, flags, 0);
 766         /* report ndisc ops about neighbour update */
 767         ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
 768 }
 769
 770 static void ndisc_recv_ns(struct sk_buff *skb)
 771 {
 772         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 773         const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 774         const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 775         u8 *lladdr = NULL;
 776         u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 777                                     offsetof(struct nd_msg, opt));
 778         struct ndisc_options ndopts;
 779         struct net_device *dev = skb->dev;
 780         struct inet6_ifaddr *ifp;
 781         struct inet6_dev *idev = NULL;
 782         struct neighbour *neigh;
 783         int dad = ipv6_addr_any(saddr);
 784         bool inc;
 785         int is_router = -1;
 786         u64 nonce = 0;
 787
 788         if (skb->len < sizeof(struct nd_msg)) {
 789                 ND_PRINTK(2, warn, "NS: packet too short\n");
 790                 return;
 791         }
 792
 793         if (ipv6_addr_is_multicast(&msg->target)) {
 794                 ND_PRINTK(2, warn, "NS: multicast target address\n");
 795                 return;
 796         }
 797
 798         /*
 799          * RFC2461 7.1.1:
 800          * DAD has to be destined for solicited node multicast address.
 801          */
 802         if (dad && !ipv6_addr_is_solict_mult(daddr)) {
 803                 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
 804                 return;
 805         }
 806
 807         if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
 808                 ND_PRINTK(2, warn, "NS: invalid ND options\n");
 809                 return;
 810         }
 811
 812         if (ndopts.nd_opts_src_lladdr) {
 813                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 814                 if (!lladdr) {
 815                         ND_PRINTK(2, warn,
 816                                   "NS: invalid link-layer address length\n");
 817                         return;
 818                 }
 819
 820                 /* RFC2461 7.1.1:
 821                  *      If the IP source address is the unspecified address,
 822                  *      there MUST NOT be source link-layer address option
 823                  *      in the message.
 824                  */
 825                 if (dad) {
 826                         ND_PRINTK(2, warn,
 827                                   "NS: bad DAD packet (link-layer address option)\n");
 828                         return;
 829                 }
 830         }
 831         if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
 832                 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
 833
 834         inc = ipv6_addr_is_multicast(daddr);
 835
 836         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 837         if (ifp) {
 838 have_ifp:
 839                 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 840                         if (dad) {
 841                                 if (nonce != 0 && ifp->dad_nonce == nonce) {
 842                                         u8 *np = (u8 *)&nonce;
 843                                         /* Matching nonce if looped back */
 844                                         ND_PRINTK(2, notice,
 845                                                   "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
 846                                                   ifp->idev->dev->name,
 847                                                   &ifp->addr, np);
 848                                         goto out;
 849                                 }
 850                                 /*
 851                                  * We are colliding with another node
 852                                  * who is doing DAD
 853                                  * so fail our DAD process
 854                                  */
 855                                 addrconf_dad_failure(skb, ifp);
 856                                 return;
 857                         } else {
 858                                 /*
 859                                  * This is not a dad solicitation.
 860                                  * If we are an optimistic node,
 861                                  * we should respond.
 862                                  * Otherwise, we should ignore it.
 863                                  */
 864                                 if (!(ifp->flags & IFA_F_OPTIMISTIC))
 865                                         goto out;
 866                         }
 867                 }
 868
 869                 idev = ifp->idev;
 870         } else {
 871                 struct net *net = dev_net(dev);
 872
 873                 /* perhaps an address on the master device */
 874                 if (netif_is_l3_slave(dev)) {
 875                         struct net_device *mdev;
 876
 877                         mdev = netdev_master_upper_dev_get_rcu(dev);
 878                         if (mdev) {
 879                                 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
 880                                 if (ifp)
 881                                         goto have_ifp;
 882                         }
 883                 }
 884
 885                 idev = in6_dev_get(dev);
 886                 if (!idev) {
 887                         /* XXX: count this drop? */
 888                         return;
 889                 }
 890
 891                 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 892                     (idev->cnf.forwarding &&
 893                      (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
 894                      (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 895                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 896                             skb->pkt_type != PACKET_HOST &&
 897                             inc &&
 898                             NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
 899                                 /*
 900                                  * for anycast or proxy,
 901                                  * sender should delay its response
 902                                  * by a random time between 0 and
 903                                  * MAX_ANYCAST_DELAY_TIME seconds.
 904                                  * (RFC2461) -- yoshfuji
 905                                  */
 906                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 907                                 if (n)
 908                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 909                                 goto out;
 910                         }
 911                 } else
 912                         goto out;
 913         }
 914
 915         if (is_router < 0)
 916                 is_router = idev->cnf.forwarding;
 917
 918         if (dad) {
 919                 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
 920                               !!is_router, false, (ifp != NULL), true);
 921                 goto out;
 922         }
 923
 924         if (inc)
 925                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 926         else
 927                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 928
 929         /*
 930          *      update / create cache entry
 931          *      for the source address
 932          */
 933         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 934                                !inc || lladdr || !dev->addr_len);
 935         if (neigh)
 936                 ndisc_update(dev, neigh, lladdr, NUD_STALE,
 937                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
 938                              NEIGH_UPDATE_F_OVERRIDE,
 939                              NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
 940         if (neigh || !dev->header_ops) {
 941                 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
 942                               true, (ifp != NULL && inc), inc);
 943                 if (neigh)
 944                         neigh_release(neigh);
 945         }
 946
 947 out:
 948         if (ifp)
 949                 in6_ifa_put(ifp);
 950         else
 951                 in6_dev_put(idev);
 952 }
 953
 954 static void ndisc_recv_na(struct sk_buff *skb)
 955 {
 956         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 957         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 958         const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 959         u8 *lladdr = NULL;
 960         u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 961                                     offsetof(struct nd_msg, opt));
 962         struct ndisc_options ndopts;
 963         struct net_device *dev = skb->dev;
 964         struct inet6_dev *idev = __in6_dev_get(dev);
 965         struct inet6_ifaddr *ifp;
 966         struct neighbour *neigh;
 967
 968         if (skb->len < sizeof(struct nd_msg)) {
 969                 ND_PRINTK(2, warn, "NA: packet too short\n");
 970                 return;
 971         }
 972
 973         if (ipv6_addr_is_multicast(&msg->target)) {
 974                 ND_PRINTK(2, warn, "NA: target address is multicast\n");
 975                 return;
 976         }
 977
 978         if (ipv6_addr_is_multicast(daddr) &&
 979             msg->icmph.icmp6_solicited) {
 980                 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
 981                 return;
 982         }
 983
 984         /* For some 802.11 wireless deployments (and possibly other networks),
 985          * there will be a NA proxy and unsolicitd packets are attacks
 986          * and thus should not be accepted.
 987          */
 988         if (!msg->icmph.icmp6_solicited && idev &&
 989             idev->cnf.drop_unsolicited_na)
 990                 return;
 991
 992         if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
 993                 ND_PRINTK(2, warn, "NS: invalid ND option\n");
 994                 return;
 995         }
 996         if (ndopts.nd_opts_tgt_lladdr) {
 997                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 998                 if (!lladdr) {
 999                         ND_PRINTK(2, warn,
1000                                   "NA: invalid link-layer address length\n");
1001                         return;
1002                 }
1003         }
1004         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1005         if (ifp) {
1006                 if (skb->pkt_type != PACKET_LOOPBACK
1007                     && (ifp->flags & IFA_F_TENTATIVE)) {
1008                                 addrconf_dad_failure(skb, ifp);
1009                                 return;
1010                 }
1011                 /* What should we make now? The advertisement
1012                    is invalid, but ndisc specs say nothing
1013                    about it. It could be misconfiguration, or
1014                    an smart proxy agent tries to help us :-)
1015
1016                    We should not print the error if NA has been
1017                    received from loopback - it is just our own
1018                    unsolicited advertisement.
1019                  */
1020                 if (skb->pkt_type != PACKET_LOOPBACK)
1021                         ND_PRINTK(1, warn,
1022                                   "NA: %pM advertised our address %pI6c on %s!\n",
1023                                   eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1024                 in6_ifa_put(ifp);
1025                 return;
1026         }
1027         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1028
1029         if (neigh) {
1030                 u8 old_flags = neigh->flags;
1031                 struct net *net = dev_net(dev);
1032
1033                 if (neigh->nud_state & NUD_FAILED)
1034                         goto out;
1035
1036                 /*
1037                  * Don't update the neighbor cache entry on a proxy NA from
1038                  * ourselves because either the proxied node is off link or it
1039                  * has already sent a NA to us.
1040                  */
1041                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1042                     net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1043                     pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1044                         /* XXX: idev->cnf.proxy_ndp */
1045                         goto out;
1046                 }
1047
1048                 ndisc_update(dev, neigh, lladdr,
1049                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1050                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1051                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1052                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1053                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1054                              NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1055
1056                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1057                         /*
1058                          * Change: router to host
1059                          */
1060                         rt6_clean_tohost(dev_net(dev),  saddr);
1061                 }
1062
1063 out:
1064                 neigh_release(neigh);
1065         }
1066 }
1067
1068 static void ndisc_recv_rs(struct sk_buff *skb)
1069 {
1070         struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1071         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1072         struct neighbour *neigh;
1073         struct inet6_dev *idev;
1074         const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1075         struct ndisc_options ndopts;
1076         u8 *lladdr = NULL;
1077
1078         if (skb->len < sizeof(*rs_msg))
1079                 return;
1080
1081         idev = __in6_dev_get(skb->dev);
1082         if (!idev) {
1083                 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1084                 return;
1085         }
1086
1087         /* Don't accept RS if we're not in router mode */
1088         if (!idev->cnf.forwarding)
1089                 goto out;
1090
1091         /*
1092          * Don't update NCE if src = ::;
1093          * this implies that the source node has no ip address assigned yet.
1094          */
1095         if (ipv6_addr_any(saddr))
1096                 goto out;
1097
1098         /* Parse ND options */
1099         if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1100                 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1101                 goto out;
1102         }
1103
1104         if (ndopts.nd_opts_src_lladdr) {
1105                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1106                                              skb->dev);
1107                 if (!lladdr)
1108                         goto out;
1109         }
1110
1111         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1112         if (neigh) {
1113                 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1114                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1115                              NEIGH_UPDATE_F_OVERRIDE|
1116                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1117                              NDISC_ROUTER_SOLICITATION, &ndopts);
1118                 neigh_release(neigh);
1119         }
1120 out:
1121         return;
1122 }
1123
1124 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1125 {
1126         struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1127         struct sk_buff *skb;
1128         struct nlmsghdr *nlh;
1129         struct nduseroptmsg *ndmsg;
1130         struct net *net = dev_net(ra->dev);
1131         int err;
1132         int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1133                                     + (opt->nd_opt_len << 3));
1134         size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1135
1136         skb = nlmsg_new(msg_size, GFP_ATOMIC);
1137         if (!skb) {
1138                 err = -ENOBUFS;
1139                 goto errout;
1140         }
1141
1142         nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1143         if (!nlh) {
1144                 goto nla_put_failure;
1145         }
1146
1147         ndmsg = nlmsg_data(nlh);
1148         ndmsg->nduseropt_family = AF_INET6;
1149         ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1150         ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1151         ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1152         ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1153
1154         memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1155
1156         if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1157                 goto nla_put_failure;
1158         nlmsg_end(skb, nlh);
1159
1160         rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1161         return;
1162
1163 nla_put_failure:
1164         nlmsg_free(skb);
1165         err = -EMSGSIZE;
1166 errout:
1167         rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1168 }
1169
1170 static void ndisc_router_discovery(struct sk_buff *skb)
1171 {
1172         struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1173         struct neighbour *neigh = NULL;
1174         struct inet6_dev *in6_dev;
1175         struct fib6_info *rt = NULL;
1176         u32 defrtr_usr_metric;
1177         struct net *net;
1178         int lifetime;
1179         struct ndisc_options ndopts;
1180         int optlen;
1181         unsigned int pref = 0;
1182         __u32 old_if_flags;
1183         bool send_ifinfo_notify = false;
1184
1185         __u8 *opt = (__u8 *)(ra_msg + 1);
1186
1187         optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1188                 sizeof(struct ra_msg);
1189
1190         ND_PRINTK(2, info,
1191                   "RA: %s, dev: %s\n",
1192                   __func__, skb->dev->name);
1193         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1194                 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1195                 return;
1196         }
1197         if (optlen < 0) {
1198                 ND_PRINTK(2, warn, "RA: packet too short\n");
1199                 return;
1200         }
1201
1202 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1203         if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1204                 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1205                 return;
1206         }
1207 #endif
1208
1209         /*
1210          *      set the RA_RECV flag in the interface
1211          */
1212
1213         in6_dev = __in6_dev_get(skb->dev);
1214         if (!in6_dev) {
1215                 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1216                           skb->dev->name);
1217                 return;
1218         }
1219
1220         if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1221                 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1222                 return;
1223         }
1224
1225         if (!ipv6_accept_ra(in6_dev)) {
1226                 ND_PRINTK(2, info,
1227                           "RA: %s, did not accept ra for dev: %s\n",
1228                           __func__, skb->dev->name);
1229                 goto skip_linkparms;
1230         }
1231
1232 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1233         /* skip link-specific parameters from interior routers */
1234         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1235                 ND_PRINTK(2, info,
1236                           "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1237                           __func__, skb->dev->name);
1238                 goto skip_linkparms;
1239         }
1240 #endif
1241
1242         if (in6_dev->if_flags & IF_RS_SENT) {
1243                 /*
1244                  *      flag that an RA was received after an RS was sent
1245                  *      out on this interface.
1246                  */
1247                 in6_dev->if_flags |= IF_RA_RCVD;
1248         }
1249
1250         /*
1251          * Remember the managed/otherconf flags from most recently
1252          * received RA message (RFC 2462) -- yoshfuji
1253          */
1254         old_if_flags = in6_dev->if_flags;
1255         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1256                                 IF_RA_OTHERCONF)) |
1257                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1258                                         IF_RA_MANAGED : 0) |
1259                                 (ra_msg->icmph.icmp6_addrconf_other ?
1260                                         IF_RA_OTHERCONF : 0);
1261
1262         if (old_if_flags != in6_dev->if_flags)
1263                 send_ifinfo_notify = true;
1264
1265         if (!in6_dev->cnf.accept_ra_defrtr) {
1266                 ND_PRINTK(2, info,
1267                           "RA: %s, defrtr is false for dev: %s\n",
1268                           __func__, skb->dev->name);
1269                 goto skip_defrtr;
1270         }
1271
1272         /* Do not accept RA with source-addr found on local machine unless
1273          * accept_ra_from_local is set to true.
1274          */
1275         net = dev_net(in6_dev->dev);
1276         if (!in6_dev->cnf.accept_ra_from_local &&
1277             ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1278                 ND_PRINTK(2, info,
1279                           "RA from local address detected on dev: %s: default router ignored\n",
1280                           skb->dev->name);
1281                 goto skip_defrtr;
1282         }
1283
1284         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1285
1286 #ifdef CONFIG_IPV6_ROUTER_PREF
1287         pref = ra_msg->icmph.icmp6_router_pref;
1288         /* 10b is handled as if it were 00b (medium) */
1289         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1290             !in6_dev->cnf.accept_ra_rtr_pref)
1291                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1292 #endif
1293         /* routes added from RAs do not use nexthop objects */
1294         rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1295         if (rt) {
1296                 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1297                                          rt->fib6_nh->fib_nh_dev, NULL,
1298                                           &ipv6_hdr(skb)->saddr);
1299                 if (!neigh) {
1300                         ND_PRINTK(0, err,
1301                                   "RA: %s got default router without neighbour\n",
1302                                   __func__);
1303                         fib6_info_release(rt);
1304                         return;
1305                 }
1306         }
1307         /* Set default route metric as specified by user */
1308         defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1309         /* delete the route if lifetime is 0 or if metric needs change */
1310         if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1311                 ip6_del_rt(net, rt, false);
1312                 rt = NULL;
1313         }
1314
1315         ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, metric: %d, for dev: %s\n",
1316                   rt, lifetime, defrtr_usr_metric, skb->dev->name);
1317         if (!rt && lifetime) {
1318                 ND_PRINTK(3, info, "RA: adding default router\n");
1319
1320                 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1321                                          skb->dev, pref, defrtr_usr_metric);
1322                 if (!rt) {
1323                         ND_PRINTK(0, err,
1324                                   "RA: %s failed to add default route\n",
1325                                   __func__);
1326                         return;
1327                 }
1328
1329                 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1330                                          rt->fib6_nh->fib_nh_dev, NULL,
1331                                           &ipv6_hdr(skb)->saddr);
1332                 if (!neigh) {
1333                         ND_PRINTK(0, err,
1334                                   "RA: %s got default router without neighbour\n",
1335                                   __func__);
1336                         fib6_info_release(rt);
1337                         return;
1338                 }
1339                 neigh->flags |= NTF_ROUTER;
1340         } else if (rt) {
1341                 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1342         }
1343
1344         if (rt)
1345                 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1346         if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1347             ra_msg->icmph.icmp6_hop_limit) {
1348                 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1349                         in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1350                         fib6_metric_set(rt, RTAX_HOPLIMIT,
1351                                         ra_msg->icmph.icmp6_hop_limit);
1352                 } else {
1353                         ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1354                 }
1355         }
1356
1357 skip_defrtr:
1358
1359         /*
1360          *      Update Reachable Time and Retrans Timer
1361          */
1362
1363         if (in6_dev->nd_parms) {
1364                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1365
1366                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1367                         rtime = (rtime*HZ)/1000;
1368                         if (rtime < HZ/100)
1369                                 rtime = HZ/100;
1370                         NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1371                         in6_dev->tstamp = jiffies;
1372                         send_ifinfo_notify = true;
1373                 }
1374
1375                 rtime = ntohl(ra_msg->reachable_time);
1376                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1377                         rtime = (rtime*HZ)/1000;
1378
1379                         if (rtime < HZ/10)
1380                                 rtime = HZ/10;
1381
1382                         if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1383                                 NEIGH_VAR_SET(in6_dev->nd_parms,
1384                                               BASE_REACHABLE_TIME, rtime);
1385                                 NEIGH_VAR_SET(in6_dev->nd_parms,
1386                                               GC_STALETIME, 3 * rtime);
1387                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1388                                 in6_dev->tstamp = jiffies;
1389                                 send_ifinfo_notify = true;
1390                         }
1391                 }
1392         }
1393
1394         /*
1395          *      Send a notify if RA changed managed/otherconf flags or timer settings
1396          */
1397         if (send_ifinfo_notify)
1398                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1399
1400 skip_linkparms:
1401
1402         /*
1403          *      Process options.
1404          */
1405
1406         if (!neigh)
1407                 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1408                                        skb->dev, 1);
1409         if (neigh) {
1410                 u8 *lladdr = NULL;
1411                 if (ndopts.nd_opts_src_lladdr) {
1412                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1413                                                      skb->dev);
1414                         if (!lladdr) {
1415                                 ND_PRINTK(2, warn,
1416                                           "RA: invalid link-layer address length\n");
1417                                 goto out;
1418                         }
1419                 }
1420                 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1421                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1422                              NEIGH_UPDATE_F_OVERRIDE|
1423                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1424                              NEIGH_UPDATE_F_ISROUTER,
1425                              NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1426         }
1427
1428         if (!ipv6_accept_ra(in6_dev)) {
1429                 ND_PRINTK(2, info,
1430                           "RA: %s, accept_ra is false for dev: %s\n",
1431                           __func__, skb->dev->name);
1432                 goto out;
1433         }
1434
1435 #ifdef CONFIG_IPV6_ROUTE_INFO
1436         if (!in6_dev->cnf.accept_ra_from_local &&
1437             ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1438                           in6_dev->dev, 0)) {
1439                 ND_PRINTK(2, info,
1440                           "RA from local address detected on dev: %s: router info ignored.\n",
1441                           skb->dev->name);
1442                 goto skip_routeinfo;
1443         }
1444
1445         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1446                 struct nd_opt_hdr *p;
1447                 for (p = ndopts.nd_opts_ri;
1448                      p;
1449                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1450                         struct route_info *ri = (struct route_info *)p;
1451 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1452                         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1453                             ri->prefix_len == 0)
1454                                 continue;
1455 #endif
1456                         if (ri->prefix_len == 0 &&
1457                             !in6_dev->cnf.accept_ra_defrtr)
1458                                 continue;
1459                         if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1460                                 continue;
1461                         if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1462                                 continue;
1463                         rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1464                                       &ipv6_hdr(skb)->saddr);
1465                 }
1466         }
1467
1468 skip_routeinfo:
1469 #endif
1470
1471 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1472         /* skip link-specific ndopts from interior routers */
1473         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1474                 ND_PRINTK(2, info,
1475                           "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1476                           __func__, skb->dev->name);
1477                 goto out;
1478         }
1479 #endif
1480
1481         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1482                 struct nd_opt_hdr *p;
1483                 for (p = ndopts.nd_opts_pi;
1484                      p;
1485                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1486                         addrconf_prefix_rcv(skb->dev, (u8 *)p,
1487                                             (p->nd_opt_len) << 3,
1488                                             ndopts.nd_opts_src_lladdr != NULL);
1489                 }
1490         }
1491
1492         if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1493                 __be32 n;
1494                 u32 mtu;
1495
1496                 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1497                 mtu = ntohl(n);
1498
1499                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1500                         ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1501                 } else if (in6_dev->cnf.mtu6 != mtu) {
1502                         in6_dev->cnf.mtu6 = mtu;
1503                         fib6_metric_set(rt, RTAX_MTU, mtu);
1504                         rt6_mtu_change(skb->dev, mtu);
1505                 }
1506         }
1507
1508         if (ndopts.nd_useropts) {
1509                 struct nd_opt_hdr *p;
1510                 for (p = ndopts.nd_useropts;
1511                      p;
1512                      p = ndisc_next_useropt(skb->dev, p,
1513                                             ndopts.nd_useropts_end)) {
1514                         ndisc_ra_useropt(skb, p);
1515                 }
1516         }
1517
1518         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1519                 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1520         }
1521 out:
1522         fib6_info_release(rt);
1523         if (neigh)
1524                 neigh_release(neigh);
1525 }
1526
1527 static void ndisc_redirect_rcv(struct sk_buff *skb)
1528 {
1529         u8 *hdr;
1530         struct ndisc_options ndopts;
1531         struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1532         u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1533                                     offsetof(struct rd_msg, opt));
1534
1535 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1536         switch (skb->ndisc_nodetype) {
1537         case NDISC_NODETYPE_HOST:
1538         case NDISC_NODETYPE_NODEFAULT:
1539                 ND_PRINTK(2, warn,
1540                           "Redirect: from host or unauthorized router\n");
1541                 return;
1542         }
1543 #endif
1544
1545         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1546                 ND_PRINTK(2, warn,
1547                           "Redirect: source address is not link-local\n");
1548                 return;
1549         }
1550
1551         if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1552                 return;
1553
1554         if (!ndopts.nd_opts_rh) {
1555                 ip6_redirect_no_header(skb, dev_net(skb->dev),
1556                                         skb->dev->ifindex);
1557                 return;
1558         }
1559
1560         hdr = (u8 *)ndopts.nd_opts_rh;
1561         hdr += 8;
1562         if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1563                 return;
1564
1565         icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1566 }
1567
1568 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1569                                            struct sk_buff *orig_skb,
1570                                            int rd_len)
1571 {
1572         u8 *opt = skb_put(skb, rd_len);
1573
1574         memset(opt, 0, 8);
1575         *(opt++) = ND_OPT_REDIRECT_HDR;
1576         *(opt++) = (rd_len >> 3);
1577         opt += 6;
1578
1579         skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1580                       rd_len - 8);
1581 }
1582
1583 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1584 {
1585         struct net_device *dev = skb->dev;
1586         struct net *net = dev_net(dev);
1587         struct sock *sk = net->ipv6.ndisc_sk;
1588         int optlen = 0;
1589         struct inet_peer *peer;
1590         struct sk_buff *buff;
1591         struct rd_msg *msg;
1592         struct in6_addr saddr_buf;
1593         struct rt6_info *rt;
1594         struct dst_entry *dst;
1595         struct flowi6 fl6;
1596         int rd_len;
1597         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1598            ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1599         bool ret;
1600
1601         if (netif_is_l3_master(skb->dev)) {
1602                 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1603                 if (!dev)
1604                         return;
1605         }
1606
1607         if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1608                 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1609                           dev->name);
1610                 return;
1611         }
1612
1613         if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1614             ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1615                 ND_PRINTK(2, warn,
1616                           "Redirect: target address is not link-local unicast\n");
1617                 return;
1618         }
1619
1620         icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1621                          &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1622
1623         dst = ip6_route_output(net, NULL, &fl6);
1624         if (dst->error) {
1625                 dst_release(dst);
1626                 return;
1627         }
1628         dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1629         if (IS_ERR(dst))
1630                 return;
1631
1632         rt = (struct rt6_info *) dst;
1633
1634         if (rt->rt6i_flags & RTF_GATEWAY) {
1635                 ND_PRINTK(2, warn,
1636                           "Redirect: destination is not a neighbour\n");
1637                 goto release;
1638         }
1639         peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1640         ret = inet_peer_xrlim_allow(peer, 1*HZ);
1641         if (peer)
1642                 inet_putpeer(peer);
1643         if (!ret)
1644                 goto release;
1645
1646         if (dev->addr_len) {
1647                 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1648                 if (!neigh) {
1649                         ND_PRINTK(2, warn,
1650                                   "Redirect: no neigh for target address\n");
1651                         goto release;
1652                 }
1653
1654                 read_lock_bh(&neigh->lock);
1655                 if (neigh->nud_state & NUD_VALID) {
1656                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1657                         read_unlock_bh(&neigh->lock);
1658                         ha = ha_buf;
1659                         optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1660                                                                 ops_data_buf,
1661                                                                 &ops_data);
1662                 } else
1663                         read_unlock_bh(&neigh->lock);
1664
1665                 neigh_release(neigh);
1666         }
1667
1668         rd_len = min_t(unsigned int,
1669                        IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1670                        skb->len + 8);
1671         rd_len &= ~0x7;
1672         optlen += rd_len;
1673
1674         buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1675         if (!buff)
1676                 goto release;
1677
1678         msg = skb_put(buff, sizeof(*msg));
1679         *msg = (struct rd_msg) {
1680                 .icmph = {
1681                         .icmp6_type = NDISC_REDIRECT,
1682                 },
1683                 .target = *target,
1684                 .dest = ipv6_hdr(skb)->daddr,
1685         };
1686
1687         /*
1688          *      include target_address option
1689          */
1690
1691         if (ha)
1692                 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1693
1694         /*
1695          *      build redirect option and copy skb over to the new packet.
1696          */
1697
1698         if (rd_len)
1699                 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1700
1701         skb_dst_set(buff, dst);
1702         ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1703         return;
1704
1705 release:
1706         dst_release(dst);
1707 }
1708
1709 static void pndisc_redo(struct sk_buff *skb)
1710 {
1711         ndisc_recv_ns(skb);
1712         kfree_skb(skb);
1713 }
1714
1715 static int ndisc_is_multicast(const void *pkey)
1716 {
1717         return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1718 }
1719
1720 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1721 {
1722         struct inet6_dev *idev = __in6_dev_get(skb->dev);
1723
1724         if (!idev)
1725                 return true;
1726         if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1727             idev->cnf.suppress_frag_ndisc) {
1728                 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1729                 return true;
1730         }
1731         return false;
1732 }
1733
1734 int ndisc_rcv(struct sk_buff *skb)
1735 {
1736         struct nd_msg *msg;
1737
1738         if (ndisc_suppress_frag_ndisc(skb))
1739                 return 0;
1740
1741         if (skb_linearize(skb))
1742                 return 0;
1743
1744         msg = (struct nd_msg *)skb_transport_header(skb);
1745
1746         __skb_push(skb, skb->data - skb_transport_header(skb));
1747
1748         if (ipv6_hdr(skb)->hop_limit != 255) {
1749                 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1750                           ipv6_hdr(skb)->hop_limit);
1751                 return 0;
1752         }
1753
1754         if (msg->icmph.icmp6_code != 0) {
1755                 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1756                           msg->icmph.icmp6_code);
1757                 return 0;
1758         }
1759
1760         switch (msg->icmph.icmp6_type) {
1761         case NDISC_NEIGHBOUR_SOLICITATION:
1762                 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1763                 ndisc_recv_ns(skb);
1764                 break;
1765
1766         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1767                 ndisc_recv_na(skb);
1768                 break;
1769
1770         case NDISC_ROUTER_SOLICITATION:
1771                 ndisc_recv_rs(skb);
1772                 break;
1773
1774         case NDISC_ROUTER_ADVERTISEMENT:
1775                 ndisc_router_discovery(skb);
1776                 break;
1777
1778         case NDISC_REDIRECT:
1779                 ndisc_redirect_rcv(skb);
1780                 break;
1781         }
1782
1783         return 0;
1784 }
1785
1786 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1787 {
1788         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1789         struct netdev_notifier_change_info *change_info;
1790         struct net *net = dev_net(dev);
1791         struct inet6_dev *idev;
1792
1793         switch (event) {
1794         case NETDEV_CHANGEADDR:
1795                 neigh_changeaddr(&nd_tbl, dev);
1796                 fib6_run_gc(0, net, false);
1797                 fallthrough;
1798         case NETDEV_UP:
1799                 idev = in6_dev_get(dev);
1800                 if (!idev)
1801                         break;
1802                 if (idev->cnf.ndisc_notify ||
1803                     net->ipv6.devconf_all->ndisc_notify)
1804                         ndisc_send_unsol_na(dev);
1805                 in6_dev_put(idev);
1806                 break;
1807         case NETDEV_CHANGE:
1808                 change_info = ptr;
1809                 if (change_info->flags_changed & IFF_NOARP)
1810                         neigh_changeaddr(&nd_tbl, dev);
1811                 if (!netif_carrier_ok(dev))
1812                         neigh_carrier_down(&nd_tbl, dev);
1813                 break;
1814         case NETDEV_DOWN:
1815                 neigh_ifdown(&nd_tbl, dev);
1816                 fib6_run_gc(0, net, false);
1817                 break;
1818         case NETDEV_NOTIFY_PEERS:
1819                 ndisc_send_unsol_na(dev);
1820                 break;
1821         default:
1822                 break;
1823         }
1824
1825         return NOTIFY_DONE;
1826 }
1827
1828 static struct notifier_block ndisc_netdev_notifier = {
1829         .notifier_call = ndisc_netdev_event,
1830         .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1831 };
1832
1833 #ifdef CONFIG_SYSCTL
1834 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1835                                          const char *func, const char *dev_name)
1836 {
1837         static char warncomm[TASK_COMM_LEN];
1838         static int warned;
1839         if (strcmp(warncomm, current->comm) && warned < 5) {
1840                 strcpy(warncomm, current->comm);
1841                 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1842                         warncomm, func,
1843                         dev_name, ctl->procname,
1844                         dev_name, ctl->procname);
1845                 warned++;
1846         }
1847 }
1848
1849 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1850                 size_t *lenp, loff_t *ppos)
1851 {
1852         struct net_device *dev = ctl->extra1;
1853         struct inet6_dev *idev;
1854         int ret;
1855
1856         if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1857             (strcmp(ctl->procname, "base_reachable_time") == 0))
1858                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1859
1860         if (strcmp(ctl->procname, "retrans_time") == 0)
1861                 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1862
1863         else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1864                 ret = neigh_proc_dointvec_jiffies(ctl, write,
1865                                                   buffer, lenp, ppos);
1866
1867         else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1868                  (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1869                 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1870                                                      buffer, lenp, ppos);
1871         else
1872                 ret = -1;
1873
1874         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1875                 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1876                         idev->nd_parms->reachable_time =
1877                                         neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1878                 idev->tstamp = jiffies;
1879                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1880                 in6_dev_put(idev);
1881         }
1882         return ret;
1883 }
1884
1885
1886 #endif
1887
1888 static int __net_init ndisc_net_init(struct net *net)
1889 {
1890         struct ipv6_pinfo *np;
1891         struct sock *sk;
1892         int err;
1893
1894         err = inet_ctl_sock_create(&sk, PF_INET6,
1895                                    SOCK_RAW, IPPROTO_ICMPV6, net);
1896         if (err < 0) {
1897                 ND_PRINTK(0, err,
1898                           "NDISC: Failed to initialize the control socket (err %d)\n",
1899                           err);
1900                 return err;
1901         }
1902
1903         net->ipv6.ndisc_sk = sk;
1904
1905         np = inet6_sk(sk);
1906         np->hop_limit = 255;
1907         /* Do not loopback ndisc messages */
1908         np->mc_loop = 0;
1909
1910         return 0;
1911 }
1912
1913 static void __net_exit ndisc_net_exit(struct net *net)
1914 {
1915         inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1916 }
1917
1918 static struct pernet_operations ndisc_net_ops = {
1919         .init = ndisc_net_init,
1920         .exit = ndisc_net_exit,
1921 };
1922
1923 int __init ndisc_init(void)
1924 {
1925         int err;
1926
1927         err = register_pernet_subsys(&ndisc_net_ops);
1928         if (err)
1929                 return err;
1930         /*
1931          * Initialize the neighbour table
1932          */
1933         neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1934
1935 #ifdef CONFIG_SYSCTL
1936         err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1937                                     ndisc_ifinfo_sysctl_change);
1938         if (err)
1939                 goto out_unregister_pernet;
1940 out:
1941 #endif
1942         return err;
1943
1944 #ifdef CONFIG_SYSCTL
1945 out_unregister_pernet:
1946         unregister_pernet_subsys(&ndisc_net_ops);
1947         goto out;
1948 #endif
1949 }
1950
1951 int __init ndisc_late_init(void)
1952 {
1953         return register_netdevice_notifier(&ndisc_netdev_notifier);
1954 }
1955
1956 void ndisc_late_cleanup(void)
1957 {
1958         unregister_netdevice_notifier(&ndisc_netdev_notifier);
1959 }
1960
1961 void ndisc_cleanup(void)
1962 {
1963 #ifdef CONFIG_SYSCTL
1964         neigh_sysctl_unregister(&nd_tbl.parms);
1965 #endif
1966         neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1967         unregister_pernet_subsys(&ndisc_net_ops);
1968 }