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_PREF64 = 38,             /* RFC8781 */
  45         __ND_OPT_MAX
  46 };
  47
  48 #define MAX_RTR_SOLICITATION_DELAY      HZ
  49
  50 #define ND_REACHABLE_TIME               (30*HZ)
  51 #define ND_RETRANS_TIMER                HZ
  52
  53 #include <linux/compiler.h>
  54 #include <linux/icmpv6.h>
  55 #include <linux/in6.h>
  56 #include <linux/types.h>
  57 #include <linux/if_arp.h>
  58 #include <linux/netdevice.h>
  59 #include <linux/hash.h>
  60
  61 #include <net/neighbour.h>
  62
  63 /* Set to 3 to get tracing... */
  64 #define ND_DEBUG 1
  65
  66 #define ND_PRINTK(val, level, fmt, ...)                         \
  67 do {                                                            \
  68         if (val <= ND_DEBUG)                                    \
  69                 net_##level##_ratelimited(fmt, ##__VA_ARGS__);  \
  70 } while (0)
  71
  72 struct ctl_table;
  73 struct inet6_dev;
  74 struct net_device;
  75 struct net_proto_family;
  76 struct sk_buff;
  77 struct prefix_info;
  78
  79 extern struct neigh_table nd_tbl;
  80
  81 struct nd_msg {
  82         struct icmp6hdr icmph;
  83         struct in6_addr target;
  84         __u8            opt[];
  85 };
  86
  87 struct rs_msg {
  88         struct icmp6hdr icmph;
  89         __u8            opt[];
  90 };
  91
  92 struct ra_msg {
  93         struct icmp6hdr         icmph;
  94         __be32                  reachable_time;
  95         __be32                  retrans_timer;
  96 };
  97
  98 struct rd_msg {
  99         struct icmp6hdr icmph;
 100         struct in6_addr target;
 101         struct in6_addr dest;
 102         __u8            opt[];
 103 };
 104
 105 struct nd_opt_hdr {
 106         __u8            nd_opt_type;
 107         __u8            nd_opt_len;
 108 } __packed;
 109
 110 /* ND options */
 111 struct ndisc_options {
 112         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 113 #ifdef CONFIG_IPV6_ROUTE_INFO
 114         struct nd_opt_hdr *nd_opts_ri;
 115         struct nd_opt_hdr *nd_opts_ri_end;
 116 #endif
 117         struct nd_opt_hdr *nd_useropts;
 118         struct nd_opt_hdr *nd_useropts_end;
 119 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 120         struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
 121 #endif
 122 };
 123
 124 #define nd_opts_src_lladdr              nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
 125 #define nd_opts_tgt_lladdr              nd_opt_array[ND_OPT_TARGET_LL_ADDR]
 126 #define nd_opts_pi                      nd_opt_array[ND_OPT_PREFIX_INFO]
 127 #define nd_opts_pi_end                  nd_opt_array[__ND_OPT_PREFIX_INFO_END]
 128 #define nd_opts_rh                      nd_opt_array[ND_OPT_REDIRECT_HDR]
 129 #define nd_opts_mtu                     nd_opt_array[ND_OPT_MTU]
 130 #define nd_opts_nonce                   nd_opt_array[ND_OPT_NONCE]
 131 #define nd_802154_opts_src_lladdr       nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
 132 #define nd_802154_opts_tgt_lladdr       nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
 133
 134 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 135
 136 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 137                                           u8 *opt, int opt_len,
 138                                           struct ndisc_options *ndopts);
 139
 140 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 141                               int data_len, int pad);
 142
 143 #define NDISC_OPS_REDIRECT_DATA_SPACE   2
 144
 145 /*
 146  * This structure defines the hooks for IPv6 neighbour discovery.
 147  * The following hooks can be defined; unless noted otherwise, they are
 148  * optional and can be filled with a null pointer.
 149  *
 150  * int (*is_useropt)(u8 nd_opt_type):
 151  *     This function is called when IPv6 decide RA userspace options. if
 152  *     this function returns 1 then the option given by nd_opt_type will
 153  *     be handled as userspace option additional to the IPv6 options.
 154  *
 155  * int (*parse_options)(const struct net_device *dev,
 156  *                      struct nd_opt_hdr *nd_opt,
 157  *                      struct ndisc_options *ndopts):
 158  *     This function is called while parsing ndisc ops and put each position
 159  *     as pointer into ndopts. If this function return unequal 0, then this
 160  *     function took care about the ndisc option, if 0 then the IPv6 ndisc
 161  *     option parser will take care about that option.
 162  *
 163  * void (*update)(const struct net_device *dev, struct neighbour *n,
 164  *                u32 flags, u8 icmp6_type,
 165  *                const struct ndisc_options *ndopts):
 166  *     This function is called when IPv6 ndisc updates the neighbour cache
 167  *     entry. Additional options which can be updated may be previously
 168  *     parsed by parse_opts callback and accessible over ndopts parameter.
 169  *
 170  * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 171  *                       struct neighbour *neigh, u8 *ha_buf,
 172  *                       u8 **ha):
 173  *     This function is called when the necessary option space will be
 174  *     calculated before allocating a skb. The parameters neigh, ha_buf
 175  *     abd ha are available on NDISC_REDIRECT messages only.
 176  *
 177  * void (*fill_addr_option)(const struct net_device *dev,
 178  *                          struct sk_buff *skb, u8 icmp6_type,
 179  *                          const u8 *ha):
 180  *     This function is called when the skb will finally fill the option
 181  *     fields inside skb. NOTE: this callback should fill the option
 182  *     fields to the skb which are previously indicated by opt_space
 183  *     parameter. That means the decision to add such option should
 184  *     not lost between these two callbacks, e.g. protected by interface
 185  *     up state.
 186  *
 187  * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 188  *                             const struct prefix_info *pinfo,
 189  *                             struct inet6_dev *in6_dev,
 190  *                             struct in6_addr *addr,
 191  *                             int addr_type, u32 addr_flags,
 192  *                             bool sllao, bool tokenized,
 193  *                             __u32 valid_lft, u32 prefered_lft,
 194  *                             bool dev_addr_generated):
 195  *     This function is called when a RA messages is received with valid
 196  *     PIO option fields and an IPv6 address will be added to the interface
 197  *     for autoconfiguration. The parameter dev_addr_generated reports about
 198  *     if the address was based on dev->dev_addr or not. This can be used
 199  *     to add a second address if link-layer operates with two link layer
 200  *     addresses. E.g. 802.15.4 6LoWPAN.
 201  */
 202 struct ndisc_ops {
 203         int     (*is_useropt)(u8 nd_opt_type);
 204         int     (*parse_options)(const struct net_device *dev,
 205                                  struct nd_opt_hdr *nd_opt,
 206                                  struct ndisc_options *ndopts);
 207         void    (*update)(const struct net_device *dev, struct neighbour *n,
 208                           u32 flags, u8 icmp6_type,
 209                           const struct ndisc_options *ndopts);
 210         int     (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 211                                   struct neighbour *neigh, u8 *ha_buf,
 212                                   u8 **ha);
 213         void    (*fill_addr_option)(const struct net_device *dev,
 214                                     struct sk_buff *skb, u8 icmp6_type,
 215                                     const u8 *ha);
 216         void    (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 217                                        const struct prefix_info *pinfo,
 218                                        struct inet6_dev *in6_dev,
 219                                        struct in6_addr *addr,
 220                                        int addr_type, u32 addr_flags,
 221                                        bool sllao, bool tokenized,
 222                                        __u32 valid_lft, u32 prefered_lft,
 223                                        bool dev_addr_generated);
 224 };
 225
 226 #if IS_ENABLED(CONFIG_IPV6)
 227 static inline int ndisc_ops_is_useropt(const struct net_device *dev,
 228                                        u8 nd_opt_type)
 229 {
 230         if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
 231                 return dev->ndisc_ops->is_useropt(nd_opt_type);
 232         else
 233                 return 0;
 234 }
 235
 236 static inline int ndisc_ops_parse_options(const struct net_device *dev,
 237                                           struct nd_opt_hdr *nd_opt,
 238                                           struct ndisc_options *ndopts)
 239 {
 240         if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
 241                 return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
 242         else
 243                 return 0;
 244 }
 245
 246 static inline void ndisc_ops_update(const struct net_device *dev,
 247                                           struct neighbour *n, u32 flags,
 248                                           u8 icmp6_type,
 249                                           const struct ndisc_options *ndopts)
 250 {
 251         if (dev->ndisc_ops && dev->ndisc_ops->update)
 252                 dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
 253 }
 254
 255 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
 256                                            u8 icmp6_type)
 257 {
 258         if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
 259             icmp6_type != NDISC_REDIRECT)
 260                 return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
 261                                                       NULL, NULL);
 262         else
 263                 return 0;
 264 }
 265
 266 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
 267                                                     struct neighbour *neigh,
 268                                                     u8 *ha_buf, u8 **ha)
 269 {
 270         if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
 271                 return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
 272                                                       neigh, ha_buf, ha);
 273         else
 274                 return 0;
 275 }
 276
 277 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
 278                                               struct sk_buff *skb,
 279                                               u8 icmp6_type)
 280 {
 281         if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
 282             icmp6_type != NDISC_REDIRECT)
 283                 dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
 284 }
 285
 286 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
 287                                                        struct sk_buff *skb,
 288                                                        const u8 *ha)
 289 {
 290         if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
 291                 dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
 292 }
 293
 294 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
 295                                                  struct net_device *dev,
 296                                                  const struct prefix_info *pinfo,
 297                                                  struct inet6_dev *in6_dev,
 298                                                  struct in6_addr *addr,
 299                                                  int addr_type, u32 addr_flags,
 300                                                  bool sllao, bool tokenized,
 301                                                  __u32 valid_lft,
 302                                                  u32 prefered_lft,
 303                                                  bool dev_addr_generated)
 304 {
 305         if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
 306                 dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
 307                                                     addr, addr_type,
 308                                                     addr_flags, sllao,
 309                                                     tokenized, valid_lft,
 310                                                     prefered_lft,
 311                                                     dev_addr_generated);
 312 }
 313 #endif
 314
 315 /*
 316  * Return the padding between the option length and the start of the
 317  * link addr.  Currently only IP-over-InfiniBand needs this, although
 318  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 319  * also need a pad of 2.
 320  */
 321 static inline int ndisc_addr_option_pad(unsigned short type)
 322 {
 323         switch (type) {
 324         case ARPHRD_INFINIBAND: return 2;
 325         default:                return 0;
 326         }
 327 }
 328
 329 static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
 330 {
 331         return NDISC_OPT_SPACE(addr_len + pad);
 332 }
 333
 334 #if IS_ENABLED(CONFIG_IPV6)
 335 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
 336 {
 337         return __ndisc_opt_addr_space(dev->addr_len,
 338                                       ndisc_addr_option_pad(dev->type)) +
 339                 ndisc_ops_opt_addr_space(dev, icmp6_type);
 340 }
 341
 342 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
 343                                                 struct neighbour *neigh,
 344                                                 u8 *ops_data_buf,
 345                                                 u8 **ops_data)
 346 {
 347         return __ndisc_opt_addr_space(dev->addr_len,
 348                                       ndisc_addr_option_pad(dev->type)) +
 349                 ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
 350                                                   ops_data);
 351 }
 352 #endif
 353
 354 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
 355                                         unsigned char addr_len, int prepad)
 356 {
 357         u8 *lladdr = (u8 *)(p + 1);
 358         int lladdrlen = p->nd_opt_len << 3;
 359         if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
 360                 return NULL;
 361         return lladdr + prepad;
 362 }
 363
 364 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 365                                       struct net_device *dev)
 366 {
 367         return __ndisc_opt_addr_data(p, dev->addr_len,
 368                                      ndisc_addr_option_pad(dev->type));
 369 }
 370
 371 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
 372 {
 373         const u32 *p32 = pkey;
 374
 375         return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
 376                 (p32[1] * hash_rnd[1]) +
 377                 (p32[2] * hash_rnd[2]) +
 378                 (p32[3] * hash_rnd[3]));
 379 }
 380
 381 static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
 382 {
 383         return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
 384 }
 385
 386 static inline
 387 struct neighbour *__ipv6_neigh_lookup_noref_stub(struct net_device *dev,
 388                                                  const void *pkey)
 389 {
 390         return ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128,
 391                                      ndisc_hashfn, pkey, dev);
 392 }
 393
 394 static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
 395 {
 396         struct neighbour *n;
 397
 398         rcu_read_lock_bh();
 399         n = __ipv6_neigh_lookup_noref(dev, pkey);
 400         if (n && !refcount_inc_not_zero(&n->refcnt))
 401                 n = NULL;
 402         rcu_read_unlock_bh();
 403
 404         return n;
 405 }
 406
 407 static inline void __ipv6_confirm_neigh(struct net_device *dev,
 408                                         const void *pkey)
 409 {
 410         struct neighbour *n;
 411
 412         rcu_read_lock_bh();
 413         n = __ipv6_neigh_lookup_noref(dev, pkey);
 414         if (n) {
 415                 unsigned long now = jiffies;
 416
 417                 /* avoid dirtying neighbour */
 418                 if (READ_ONCE(n->confirmed) != now)
 419                         WRITE_ONCE(n->confirmed, now);
 420         }
 421         rcu_read_unlock_bh();
 422 }
 423
 424 static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
 425                                              const void *pkey)
 426 {
 427         struct neighbour *n;
 428
 429         rcu_read_lock_bh();
 430         n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
 431         if (n) {
 432                 unsigned long now = jiffies;
 433
 434                 /* avoid dirtying neighbour */
 435                 if (READ_ONCE(n->confirmed) != now)
 436                         WRITE_ONCE(n->confirmed, now);
 437         }
 438         rcu_read_unlock_bh();
 439 }
 440
 441 /* uses ipv6_stub and is meant for use outside of IPv6 core */
 442 static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
 443                                              const void *addr)
 444 {
 445         struct neighbour *neigh;
 446
 447         neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
 448         if (unlikely(!neigh))
 449                 neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
 450
 451         return neigh;
 452 }
 453
 454 int ndisc_init(void);
 455 int ndisc_late_init(void);
 456
 457 void ndisc_late_cleanup(void);
 458 void ndisc_cleanup(void);
 459
 460 int ndisc_rcv(struct sk_buff *skb);
 461
 462 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 463                    const struct in6_addr *daddr, const struct in6_addr *saddr,
 464                    u64 nonce);
 465
 466 void ndisc_send_rs(struct net_device *dev,
 467                    const struct in6_addr *saddr, const struct in6_addr *daddr);
 468 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 469                    const struct in6_addr *solicited_addr,
 470                    bool router, bool solicited, bool override, bool inc_opt);
 471
 472 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
 473
 474 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
 475                  int dir);
 476
 477 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 478                   const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 479                   struct ndisc_options *ndopts);
 480
 481 /*
 482  *      IGMP
 483  */
 484 int igmp6_init(void);
 485 int igmp6_late_init(void);
 486
 487 void igmp6_cleanup(void);
 488 void igmp6_late_cleanup(void);
 489
 490 int igmp6_event_query(struct sk_buff *skb);
 491
 492 int igmp6_event_report(struct sk_buff *skb);
 493
 494
 495 #ifdef CONFIG_SYSCTL
 496 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
 497                                void *buffer, size_t *lenp, loff_t *ppos);
 498 int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
 499                                  void __user *oldval, size_t __user *oldlenp,
 500                                  void __user *newval, size_t newlen);
 501 #endif
 502
 503 void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
 504
 505 #endif