include/net/ndisc.h

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