include/net/ndisc.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _NDISC_H
   3 #define _NDISC_H
   4
   5 #include <net/ipv6_stubs.h>
   6
   7 /*
   8  *      ICMP codes for neighbour discovery messages
   9  */
  10
  11 #define NDISC_ROUTER_SOLICITATION       133
  12 #define NDISC_ROUTER_ADVERTISEMENT      134
  13 #define NDISC_NEIGHBOUR_SOLICITATION    135
  14 #define NDISC_NEIGHBOUR_ADVERTISEMENT   136
  15 #define NDISC_REDIRECT                  137
  16
  17 /*
  18  * Router type: cross-layer information from link-layer to
  19  * IPv6 layer reported by certain link types (e.g., RFC4214).
  20  */
  21 #define NDISC_NODETYPE_UNSPEC           0       /* unspecified (default) */
  22 #define NDISC_NODETYPE_HOST             1       /* host or unauthorized router */
  23 #define NDISC_NODETYPE_NODEFAULT        2       /* non-default router */
  24 #define NDISC_NODETYPE_DEFAULT          3       /* default router */
  25
  26 /*
  27  *      ndisc options
  28  */
  29
  30 enum {
  31         __ND_OPT_PREFIX_INFO_END = 0,
  32         ND_OPT_SOURCE_LL_ADDR = 1,      /* RFC2461 */
  33         ND_OPT_TARGET_LL_ADDR = 2,      /* RFC2461 */
  34         ND_OPT_PREFIX_INFO = 3,         /* RFC2461 */
  35         ND_OPT_REDIRECT_HDR = 4,        /* RFC2461 */
  36         ND_OPT_MTU = 5,                 /* RFC2461 */
  37         ND_OPT_NONCE = 14,              /* RFC7527 */
  38         __ND_OPT_ARRAY_MAX,
  39         ND_OPT_ROUTE_INFO = 24,         /* RFC4191 */
  40         ND_OPT_RDNSS = 25,              /* RFC5006 */
  41         ND_OPT_DNSSL = 31,              /* RFC6106 */
  42         ND_OPT_6CO = 34,                /* RFC6775 */
  43         ND_OPT_CAPTIVE_PORTAL = 37,     /* RFC7710 */
  44         __ND_OPT_MAX
  45 };
  46
  47 #define MAX_RTR_SOLICITATION_DELAY      HZ
  48
  49 #define ND_REACHABLE_TIME               (30*HZ)
  50 #define ND_RETRANS_TIMER                HZ
  51
  52 #include <linux/compiler.h>
  53 #include <linux/icmpv6.h>
  54 #include <linux/in6.h>
  55 #include <linux/types.h>
  56 #include <linux/if_arp.h>
  57 #include <linux/netdevice.h>
  58 #include <linux/hash.h>
  59
  60 #include <net/neighbour.h>
  61
  62 /* Set to 3 to get tracing... */
  63 #define ND_DEBUG 1
  64
  65 #define ND_PRINTK(val, level, fmt, ...)                         \
  66 do {                                                            \
  67         if (val <= ND_DEBUG)                                    \
  68                 net_##level##_ratelimited(fmt, ##__VA_ARGS__);  \
  69 } while (0)
  70
  71 struct ctl_table;
  72 struct inet6_dev;
  73 struct net_device;
  74 struct net_proto_family;
  75 struct sk_buff;
  76 struct prefix_info;
  77
  78 extern struct neigh_table nd_tbl;
  79
  80 struct nd_msg {
  81         struct icmp6hdr icmph;
  82         struct in6_addr target;
  83         __u8            opt[0];
  84 };
  85
  86 struct rs_msg {
  87         struct icmp6hdr icmph;
  88         __u8            opt[0];
  89 };
  90
  91 struct ra_msg {
  92         struct icmp6hdr         icmph;
  93         __be32                  reachable_time;
  94         __be32                  retrans_timer;
  95 };
  96
  97 struct rd_msg {
  98         struct icmp6hdr icmph;
  99         struct in6_addr target;
 100         struct in6_addr dest;
 101         __u8            opt[0];
 102 };
 103
 104 struct nd_opt_hdr {
 105         __u8            nd_opt_type;
 106         __u8            nd_opt_len;
 107 } __packed;
 108
 109 /* ND options */
 110 struct ndisc_options {
 111         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 112 #ifdef CONFIG_IPV6_ROUTE_INFO
 113         struct nd_opt_hdr *nd_opts_ri;
 114         struct nd_opt_hdr *nd_opts_ri_end;
 115 #endif
 116         struct nd_opt_hdr *nd_useropts;
 117         struct nd_opt_hdr *nd_useropts_end;
 118 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 119         struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
 120 #endif
 121 };
 122
 123 #define nd_opts_src_lladdr              nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
 124 #define nd_opts_tgt_lladdr              nd_opt_array[ND_OPT_TARGET_LL_ADDR]
 125 #define nd_opts_pi                      nd_opt_array[ND_OPT_PREFIX_INFO]
 126 #define nd_opts_pi_end                  nd_opt_array[__ND_OPT_PREFIX_INFO_END]
 127 #define nd_opts_rh                      nd_opt_array[ND_OPT_REDIRECT_HDR]
 128 #define nd_opts_mtu                     nd_opt_array[ND_OPT_MTU]
 129 #define nd_opts_nonce                   nd_opt_array[ND_OPT_NONCE]
 130 #define nd_802154_opts_src_lladdr       nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
 131 #define nd_802154_opts_tgt_lladdr       nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
 132
 133 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 134
 135 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 136                                           u8 *opt, int opt_len,
 137                                           struct ndisc_options *ndopts);
 138
 139 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 140                               int data_len, int pad);
 141
 142 #define NDISC_OPS_REDIRECT_DATA_SPACE   2
 143
 144 /*
 145  * This structure defines the hooks for IPv6 neighbour discovery.
 146  * The following hooks can be defined; unless noted otherwise, they are
 147  * optional and can be filled with a null pointer.
 148  *
 149  * int (*is_useropt)(u8 nd_opt_type):
 150  *     This function is called when IPv6 decide RA userspace options. if
 151  *     this function returns 1 then the option given by nd_opt_type will
 152  *     be handled as userspace option additional to the IPv6 options.
 153  *
 154  * int (*parse_options)(const struct net_device *dev,
 155  *                      struct nd_opt_hdr *nd_opt,
 156  *                      struct ndisc_options *ndopts):
 157  *     This function is called while parsing ndisc ops and put each position
 158  *     as pointer into ndopts. If this function return unequal 0, then this
 159  *     function took care about the ndisc option, if 0 then the IPv6 ndisc
 160  *     option parser will take care about that option.
 161  *
 162  * void (*update)(const struct net_device *dev, struct neighbour *n,
 163  *                u32 flags, u8 icmp6_type,
 164  *                const struct ndisc_options *ndopts):
 165  *     This function is called when IPv6 ndisc updates the neighbour cache
 166  *     entry. Additional options which can be updated may be previously
 167  *     parsed by parse_opts callback and accessible over ndopts parameter.
 168  *
 169  * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 170  *                       struct neighbour *neigh, u8 *ha_buf,
 171  *                       u8 **ha):
 172  *     This function is called when the necessary option space will be
 173  *     calculated before allocating a skb. The parameters neigh, ha_buf
 174  *     abd ha are available on NDISC_REDIRECT messages only.
 175  *
 176  * void (*fill_addr_option)(const struct net_device *dev,
 177  *                          struct sk_buff *skb, u8 icmp6_type,
 178  *                          const u8 *ha):
 179  *     This function is called when the skb will finally fill the option
 180  *     fields inside skb. NOTE: this callback should fill the option
 181  *     fields to the skb which are previously indicated by opt_space
 182  *     parameter. That means the decision to add such option should
 183  *     not lost between these two callbacks, e.g. protected by interface
 184  *     up state.
 185  *
 186  * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 187  *                             const struct prefix_info *pinfo,
 188  *                             struct inet6_dev *in6_dev,
 189  *                             struct in6_addr *addr,
 190  *                             int addr_type, u32 addr_flags,
 191  *                             bool sllao, bool tokenized,
 192  *                             __u32 valid_lft, u32 prefered_lft,
 193  *                             bool dev_addr_generated):
 194  *     This function is called when a RA messages is received with valid
 195  *     PIO option fields and an IPv6 address will be added to the interface
 196  *     for autoconfiguration. The parameter dev_addr_generated reports about
 197  *     if the address was based on dev->dev_addr or not. This can be used
 198  *     to add a second address if link-layer operates with two link layer
 199  *     addresses. E.g. 802.15.4 6LoWPAN.
 200  */
 201 struct ndisc_ops {
 202         int     (*is_useropt)(u8 nd_opt_type);
 203         int     (*parse_options)(const struct net_device *dev,
 204                                  struct nd_opt_hdr *nd_opt,
 205                                  struct ndisc_options *ndopts);
 206         void    (*update)(const struct net_device *dev, struct neighbour *n,
 207                           u32 flags, u8 icmp6_type,
 208                           const struct ndisc_options *ndopts);
 209         int     (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 210                                   struct neighbour *neigh, u8 *ha_buf,
 211                                   u8 **ha);
 212         void    (*fill_addr_option)(const struct net_device *dev,
 213                                     struct sk_buff *skb, u8 icmp6_type,
 214                                     const u8 *ha);
 215         void    (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 216                                        const struct prefix_info *pinfo,
 217                                        struct inet6_dev *in6_dev,
 218                                        struct in6_addr *addr,
 219                                        int addr_type, u32 addr_flags,
 220                                        bool sllao, bool tokenized,
 221                                        __u32 valid_lft, u32 prefered_lft,
 222                                        bool dev_addr_generated);
 223 };
 224
 225 #if IS_ENABLED(CONFIG_IPV6)
 226 static inline int ndisc_ops_is_useropt(const struct net_device *dev,
 227                                        u8 nd_opt_type)
 228 {
 229         if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
 230                 return dev->ndisc_ops->is_useropt(nd_opt_type);
 231         else
 232                 return 0;
 233 }
 234
 235 static inline int ndisc_ops_parse_options(const struct net_device *dev,
 236                                           struct nd_opt_hdr *nd_opt,
 237                                           struct ndisc_options *ndopts)
 238 {
 239         if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
 240                 return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
 241         else
 242                 return 0;
 243 }
 244
 245 static inline void ndisc_ops_update(const struct net_device *dev,
 246                                           struct neighbour *n, u32 flags,
 247                                           u8 icmp6_type,
 248                                           const struct ndisc_options *ndopts)
 249 {
 250         if (dev->ndisc_ops && dev->ndisc_ops->update)
 251                 dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
 252 }
 253
 254 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
 255                                            u8 icmp6_type)
 256 {
 257         if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
 258             icmp6_type != NDISC_REDIRECT)
 259                 return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
 260                                                       NULL, NULL);
 261         else
 262                 return 0;
 263 }
 264
 265 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
 266                                                     struct neighbour *neigh,
 267                                                     u8 *ha_buf, u8 **ha)
 268 {
 269         if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
 270                 return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
 271                                                       neigh, ha_buf, ha);
 272         else
 273                 return 0;
 274 }
 275
 276 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
 277                                               struct sk_buff *skb,
 278                                               u8 icmp6_type)
 279 {
 280         if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
 281             icmp6_type != NDISC_REDIRECT)
 282                 dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
 283 }
 284
 285 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
 286                                                        struct sk_buff *skb,
 287                                                        const u8 *ha)
 288 {
 289         if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
 290                 dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
 291 }
 292
 293 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
 294                                                  struct net_device *dev,
 295                                                  const struct prefix_info *pinfo,
 296                                                  struct inet6_dev *in6_dev,
 297                                                  struct in6_addr *addr,
 298                                                  int addr_type, u32 addr_flags,
 299                                                  bool sllao, bool tokenized,
 300                                                  __u32 valid_lft,
 301                                                  u32 prefered_lft,
 302                                                  bool dev_addr_generated)
 303 {
 304         if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
 305                 dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
 306                                                     addr, addr_type,
 307                                                     addr_flags, sllao,
 308                                                     tokenized, valid_lft,
 309                                                     prefered_lft,
 310                                                     dev_addr_generated);
 311 }
 312 #endif
 313
 314 /*
 315  * Return the padding between the option length and the start of the
 316  * link addr.  Currently only IP-over-InfiniBand needs this, although
 317  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 318  * also need a pad of 2.
 319  */
 320 static inline int ndisc_addr_option_pad(unsigned short type)
 321 {
 322         switch (type) {
 323         case ARPHRD_INFINIBAND: return 2;
 324         default:                return 0;
 325         }
 326 }
 327
 328 static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
 329 {
 330         return NDISC_OPT_SPACE(addr_len + pad);
 331 }
 332
 333 #if IS_ENABLED(CONFIG_IPV6)
 334 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
 335 {
 336         return __ndisc_opt_addr_space(dev->addr_len,
 337                                       ndisc_addr_option_pad(dev->type)) +
 338                 ndisc_ops_opt_addr_space(dev, icmp6_type);
 339 }
 340
 341 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
 342                                                 struct neighbour *neigh,
 343                                                 u8 *ops_data_buf,
 344                                                 u8 **ops_data)
 345 {
 346         return __ndisc_opt_addr_space(dev->addr_len,
 347                                       ndisc_addr_option_pad(dev->type)) +
 348                 ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
 349                                                   ops_data);
 350 }
 351 #endif
 352
 353 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
 354                                         unsigned char addr_len, int prepad)
 355 {
 356         u8 *lladdr = (u8 *)(p + 1);
 357         int lladdrlen = p->nd_opt_len << 3;
 358         if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
 359                 return NULL;
 360         return lladdr + prepad;
 361 }
 362
 363 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 364                                       struct net_device *dev)
 365 {
 366         return __ndisc_opt_addr_data(p, dev->addr_len,
 367                                      ndisc_addr_option_pad(dev->type));
 368 }
 369
 370 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
 371 {
 372         const u32 *p32 = pkey;
 373
 374         return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
 375                 (p32[1] * hash_rnd[1]) +
 376                 (p32[2] * hash_rnd[2]) +
 377                 (p32[3] * hash_rnd[3]));
 378 }
 379
 380 static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
 381 {
 382         return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
 383 }
 384
 385 static inline
 386 struct neighbour *__ipv6_neigh_lookup_noref_stub(struct net_device *dev,
 387                                                  const void *pkey)
 388 {
 389         return ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128,
 390                                      ndisc_hashfn, pkey, dev);
 391 }
 392
 393 static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
 394 {
 395         struct neighbour *n;
 396
 397         rcu_read_lock_bh();
 398         n = __ipv6_neigh_lookup_noref(dev, pkey);
 399         if (n && !refcount_inc_not_zero(&n->refcnt))
 400                 n = NULL;
 401         rcu_read_unlock_bh();
 402
 403         return n;
 404 }
 405
 406 static inline void __ipv6_confirm_neigh(struct net_device *dev,
 407                                         const void *pkey)
 408 {
 409         struct neighbour *n;
 410
 411         rcu_read_lock_bh();
 412         n = __ipv6_neigh_lookup_noref(dev, pkey);
 413         if (n) {
 414                 unsigned long now = jiffies;
 415
 416                 /* avoid dirtying neighbour */
 417                 if (READ_ONCE(n->confirmed) != now)
 418                         WRITE_ONCE(n->confirmed, now);
 419         }
 420         rcu_read_unlock_bh();
 421 }
 422
 423 static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
 424                                              const void *pkey)
 425 {
 426         struct neighbour *n;
 427
 428         rcu_read_lock_bh();
 429         n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
 430         if (n) {
 431                 unsigned long now = jiffies;
 432
 433                 /* avoid dirtying neighbour */
 434                 if (READ_ONCE(n->confirmed) != now)
 435                         WRITE_ONCE(n->confirmed, now);
 436         }
 437         rcu_read_unlock_bh();
 438 }
 439
 440 /* uses ipv6_stub and is meant for use outside of IPv6 core */
 441 static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
 442                                              const void *addr)
 443 {
 444         struct neighbour *neigh;
 445
 446         neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
 447         if (unlikely(!neigh))
 448                 neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
 449
 450         return neigh;
 451 }
 452
 453 int ndisc_init(void);
 454 int ndisc_late_init(void);
 455
 456 void ndisc_late_cleanup(void);
 457 void ndisc_cleanup(void);
 458
 459 int ndisc_rcv(struct sk_buff *skb);
 460
 461 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 462                    const struct in6_addr *daddr, const struct in6_addr *saddr,
 463                    u64 nonce);
 464
 465 void ndisc_send_rs(struct net_device *dev,
 466                    const struct in6_addr *saddr, const struct in6_addr *daddr);
 467 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 468                    const struct in6_addr *solicited_addr,
 469                    bool router, bool solicited, bool override, bool inc_opt);
 470
 471 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
 472
 473 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
 474                  int dir);
 475
 476 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 477                   const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 478                   struct ndisc_options *ndopts);
 479
 480 /*
 481  *      IGMP
 482  */
 483 int igmp6_init(void);
 484 int igmp6_late_init(void);
 485
 486 void igmp6_cleanup(void);
 487 void igmp6_late_cleanup(void);
 488
 489 int igmp6_event_query(struct sk_buff *skb);
 490
 491 int igmp6_event_report(struct sk_buff *skb);
 492
 493
 494 #ifdef CONFIG_SYSCTL
 495 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
 496                                void __user *buffer, size_t *lenp, loff_t *ppos);
 497 int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
 498                                  void __user *oldval, size_t __user *oldlenp,
 499                                  void __user *newval, size_t newlen);
 500 #endif
 501
 502 void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
 503
 504 #endif