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