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, const 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 (*parse_options)(const struct net_device *dev,
 151  *                      struct nd_opt_hdr *nd_opt,
 152  *                      struct ndisc_options *ndopts):
 153  *     This function is called while parsing ndisc ops and put each position
 154  *     as pointer into ndopts. If this function return unequal 0, then this
 155  *     function took care about the ndisc option, if 0 then the IPv6 ndisc
 156  *     option parser will take care about that option.
 157  *
 158  * void (*update)(const struct net_device *dev, struct neighbour *n,
 159  *                u32 flags, u8 icmp6_type,
 160  *                const struct ndisc_options *ndopts):
 161  *     This function is called when IPv6 ndisc updates the neighbour cache
 162  *     entry. Additional options which can be updated may be previously
 163  *     parsed by parse_opts callback and accessible over ndopts parameter.
 164  *
 165  * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 166  *                       struct neighbour *neigh, u8 *ha_buf,
 167  *                       u8 **ha):
 168  *     This function is called when the necessary option space will be
 169  *     calculated before allocating a skb. The parameters neigh, ha_buf
 170  *     abd ha are available on NDISC_REDIRECT messages only.
 171  *
 172  * void (*fill_addr_option)(const struct net_device *dev,
 173  *                          struct sk_buff *skb, u8 icmp6_type,
 174  *                          const u8 *ha):
 175  *     This function is called when the skb will finally fill the option
 176  *     fields inside skb. NOTE: this callback should fill the option
 177  *     fields to the skb which are previously indicated by opt_space
 178  *     parameter. That means the decision to add such option should
 179  *     not lost between these two callbacks, e.g. protected by interface
 180  *     up state.
 181  *
 182  * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 183  *                             const struct prefix_info *pinfo,
 184  *                             struct inet6_dev *in6_dev,
 185  *                             struct in6_addr *addr,
 186  *                             int addr_type, u32 addr_flags,
 187  *                             bool sllao, bool tokenized,
 188  *                             __u32 valid_lft, u32 prefered_lft,
 189  *                             bool dev_addr_generated):
 190  *     This function is called when a RA messages is received with valid
 191  *     PIO option fields and an IPv6 address will be added to the interface
 192  *     for autoconfiguration. The parameter dev_addr_generated reports about
 193  *     if the address was based on dev->dev_addr or not. This can be used
 194  *     to add a second address if link-layer operates with two link layer
 195  *     addresses. E.g. 802.15.4 6LoWPAN.
 196  */
 197 struct ndisc_ops {
 198         int     (*parse_options)(const struct net_device *dev,
 199                                  struct nd_opt_hdr *nd_opt,
 200                                  struct ndisc_options *ndopts);
 201         void    (*update)(const struct net_device *dev, struct neighbour *n,
 202                           u32 flags, u8 icmp6_type,
 203                           const struct ndisc_options *ndopts);
 204         int     (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 205                                   struct neighbour *neigh, u8 *ha_buf,
 206                                   u8 **ha);
 207         void    (*fill_addr_option)(const struct net_device *dev,
 208                                     struct sk_buff *skb, u8 icmp6_type,
 209                                     const u8 *ha);
 210         void    (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 211                                        const struct prefix_info *pinfo,
 212                                        struct inet6_dev *in6_dev,
 213                                        struct in6_addr *addr,
 214                                        int addr_type, u32 addr_flags,
 215                                        bool sllao, bool tokenized,
 216                                        __u32 valid_lft, u32 prefered_lft,
 217                                        bool dev_addr_generated);
 218 };
 219
 220 #if IS_ENABLED(CONFIG_IPV6)
 221 static inline int ndisc_ops_parse_options(const struct net_device *dev,
 222                                           struct nd_opt_hdr *nd_opt,
 223                                           struct ndisc_options *ndopts)
 224 {
 225         if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
 226                 return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
 227         else
 228                 return 0;
 229 }
 230
 231 static inline void ndisc_ops_update(const struct net_device *dev,
 232                                           struct neighbour *n, u32 flags,
 233                                           u8 icmp6_type,
 234                                           const struct ndisc_options *ndopts)
 235 {
 236         if (dev->ndisc_ops && dev->ndisc_ops->update)
 237                 dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
 238 }
 239
 240 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
 241                                            u8 icmp6_type)
 242 {
 243         if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
 244             icmp6_type != NDISC_REDIRECT)
 245                 return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
 246                                                       NULL, NULL);
 247         else
 248                 return 0;
 249 }
 250
 251 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
 252                                                     struct neighbour *neigh,
 253                                                     u8 *ha_buf, u8 **ha)
 254 {
 255         if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
 256                 return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
 257                                                       neigh, ha_buf, ha);
 258         else
 259                 return 0;
 260 }
 261
 262 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
 263                                               struct sk_buff *skb,
 264                                               u8 icmp6_type)
 265 {
 266         if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
 267             icmp6_type != NDISC_REDIRECT)
 268                 dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
 269 }
 270
 271 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
 272                                                        struct sk_buff *skb,
 273                                                        const u8 *ha)
 274 {
 275         if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
 276                 dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
 277 }
 278
 279 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
 280                                                  struct net_device *dev,
 281                                                  const struct prefix_info *pinfo,
 282                                                  struct inet6_dev *in6_dev,
 283                                                  struct in6_addr *addr,
 284                                                  int addr_type, u32 addr_flags,
 285                                                  bool sllao, bool tokenized,
 286                                                  __u32 valid_lft,
 287                                                  u32 prefered_lft,
 288                                                  bool dev_addr_generated)
 289 {
 290         if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
 291                 dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
 292                                                     addr, addr_type,
 293                                                     addr_flags, sllao,
 294                                                     tokenized, valid_lft,
 295                                                     prefered_lft,
 296                                                     dev_addr_generated);
 297 }
 298 #endif
 299
 300 /*
 301  * Return the padding between the option length and the start of the
 302  * link addr.  Currently only IP-over-InfiniBand needs this, although
 303  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 304  * also need a pad of 2.
 305  */
 306 static inline int ndisc_addr_option_pad(unsigned short type)
 307 {
 308         switch (type) {
 309         case ARPHRD_INFINIBAND: return 2;
 310         default:                return 0;
 311         }
 312 }
 313
 314 static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
 315 {
 316         return NDISC_OPT_SPACE(addr_len + pad);
 317 }
 318
 319 #if IS_ENABLED(CONFIG_IPV6)
 320 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
 321 {
 322         return __ndisc_opt_addr_space(dev->addr_len,
 323                                       ndisc_addr_option_pad(dev->type)) +
 324                 ndisc_ops_opt_addr_space(dev, icmp6_type);
 325 }
 326
 327 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
 328                                                 struct neighbour *neigh,
 329                                                 u8 *ops_data_buf,
 330                                                 u8 **ops_data)
 331 {
 332         return __ndisc_opt_addr_space(dev->addr_len,
 333                                       ndisc_addr_option_pad(dev->type)) +
 334                 ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
 335                                                   ops_data);
 336 }
 337 #endif
 338
 339 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
 340                                         unsigned char addr_len, int prepad)
 341 {
 342         u8 *lladdr = (u8 *)(p + 1);
 343         int lladdrlen = p->nd_opt_len << 3;
 344         if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
 345                 return NULL;
 346         return lladdr + prepad;
 347 }
 348
 349 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 350                                       struct net_device *dev)
 351 {
 352         return __ndisc_opt_addr_data(p, dev->addr_len,
 353                                      ndisc_addr_option_pad(dev->type));
 354 }
 355
 356 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
 357 {
 358         const u32 *p32 = pkey;
 359
 360         return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
 361                 (p32[1] * hash_rnd[1]) +
 362                 (p32[2] * hash_rnd[2]) +
 363                 (p32[3] * hash_rnd[3]));
 364 }
 365
 366 static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
 367 {
 368         return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
 369 }
 370
 371 static inline
 372 struct neighbour *__ipv6_neigh_lookup_noref_stub(struct net_device *dev,
 373                                                  const void *pkey)
 374 {
 375         return ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128,
 376                                      ndisc_hashfn, pkey, dev);
 377 }
 378
 379 static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
 380 {
 381         struct neighbour *n;
 382
 383         rcu_read_lock();
 384         n = __ipv6_neigh_lookup_noref(dev, pkey);
 385         if (n && !refcount_inc_not_zero(&n->refcnt))
 386                 n = NULL;
 387         rcu_read_unlock();
 388
 389         return n;
 390 }
 391
 392 static inline void __ipv6_confirm_neigh(struct net_device *dev,
 393                                         const void *pkey)
 394 {
 395         struct neighbour *n;
 396
 397         rcu_read_lock();
 398         n = __ipv6_neigh_lookup_noref(dev, pkey);
 399         neigh_confirm(n);
 400         rcu_read_unlock();
 401 }
 402
 403 static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
 404                                              const void *pkey)
 405 {
 406         struct neighbour *n;
 407
 408         rcu_read_lock();
 409         n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
 410         neigh_confirm(n);
 411         rcu_read_unlock();
 412 }
 413
 414 /* uses ipv6_stub and is meant for use outside of IPv6 core */
 415 static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
 416                                              const void *addr)
 417 {
 418         struct neighbour *neigh;
 419
 420         neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
 421         if (unlikely(!neigh))
 422                 neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
 423
 424         return neigh;
 425 }
 426
 427 int ndisc_init(void);
 428 int ndisc_late_init(void);
 429
 430 void ndisc_late_cleanup(void);
 431 void ndisc_cleanup(void);
 432
 433 enum skb_drop_reason ndisc_rcv(struct sk_buff *skb);
 434
 435 struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
 436                                 const struct in6_addr *saddr, u64 nonce);
 437 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 438                    const struct in6_addr *daddr, const struct in6_addr *saddr,
 439                    u64 nonce);
 440
 441 void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
 442                     const struct in6_addr *saddr);
 443
 444 void ndisc_send_rs(struct net_device *dev,
 445                    const struct in6_addr *saddr, const struct in6_addr *daddr);
 446 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 447                    const struct in6_addr *solicited_addr,
 448                    bool router, bool solicited, bool override, bool inc_opt);
 449
 450 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
 451
 452 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
 453                  int dir);
 454
 455 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 456                   const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 457                   struct ndisc_options *ndopts);
 458
 459 /*
 460  *      IGMP
 461  */
 462 int igmp6_init(void);
 463 int igmp6_late_init(void);
 464
 465 void igmp6_cleanup(void);
 466 void igmp6_late_cleanup(void);
 467
 468 void igmp6_event_query(struct sk_buff *skb);
 469
 470 void igmp6_event_report(struct sk_buff *skb);
 471
 472
 473 #ifdef CONFIG_SYSCTL
 474 int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write,
 475                                void *buffer, size_t *lenp, loff_t *ppos);
 476 #endif
 477
 478 void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
 479
 480 #endif