include/net/ndisc.h

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