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_MAX
  44 };
  45
  46 #define MAX_RTR_SOLICITATION_DELAY      HZ
  47
  48 #define ND_REACHABLE_TIME               (30*HZ)
  49 #define ND_RETRANS_TIMER                HZ
  50
  51 #include <linux/compiler.h>
  52 #include <linux/icmpv6.h>
  53 #include <linux/in6.h>
  54 #include <linux/types.h>
  55 #include <linux/if_arp.h>
  56 #include <linux/netdevice.h>
  57 #include <linux/hash.h>
  58
  59 #include <net/neighbour.h>
  60
  61 /* Set to 3 to get tracing... */
  62 #define ND_DEBUG 1
  63
  64 #define ND_PRINTK(val, level, fmt, ...)                         \
  65 do {                                                            \
  66         if (val <= ND_DEBUG)                                    \
  67                 net_##level##_ratelimited(fmt, ##__VA_ARGS__);  \
  68 } while (0)
  69
  70 struct ctl_table;
  71 struct inet6_dev;
  72 struct net_device;
  73 struct net_proto_family;
  74 struct sk_buff;
  75 struct prefix_info;
  76
  77 extern struct neigh_table nd_tbl;
  78
  79 struct nd_msg {
  80         struct icmp6hdr icmph;
  81         struct in6_addr target;
  82         __u8            opt[0];
  83 };
  84
  85 struct rs_msg {
  86         struct icmp6hdr icmph;
  87         __u8            opt[0];
  88 };
  89
  90 struct ra_msg {
  91         struct icmp6hdr         icmph;
  92         __be32                  reachable_time;
  93         __be32                  retrans_timer;
  94 };
  95
  96 struct rd_msg {
  97         struct icmp6hdr icmph;
  98         struct in6_addr target;
  99         struct in6_addr dest;
 100         __u8            opt[0];
 101 };
 102
 103 struct nd_opt_hdr {
 104         __u8            nd_opt_type;
 105         __u8            nd_opt_len;
 106 } __packed;
 107
 108 /* ND options */
 109 struct ndisc_options {
 110         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 111 #ifdef CONFIG_IPV6_ROUTE_INFO
 112         struct nd_opt_hdr *nd_opts_ri;
 113         struct nd_opt_hdr *nd_opts_ri_end;
 114 #endif
 115         struct nd_opt_hdr *nd_useropts;
 116         struct nd_opt_hdr *nd_useropts_end;
 117 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 118         struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
 119 #endif
 120 };
 121
 122 #define nd_opts_src_lladdr              nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
 123 #define nd_opts_tgt_lladdr              nd_opt_array[ND_OPT_TARGET_LL_ADDR]
 124 #define nd_opts_pi                      nd_opt_array[ND_OPT_PREFIX_INFO]
 125 #define nd_opts_pi_end                  nd_opt_array[__ND_OPT_PREFIX_INFO_END]
 126 #define nd_opts_rh                      nd_opt_array[ND_OPT_REDIRECT_HDR]
 127 #define nd_opts_mtu                     nd_opt_array[ND_OPT_MTU]
 128 #define nd_opts_nonce                   nd_opt_array[ND_OPT_NONCE]
 129 #define nd_802154_opts_src_lladdr       nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
 130 #define nd_802154_opts_tgt_lladdr       nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
 131
 132 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 133
 134 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 135                                           u8 *opt, int opt_len,
 136                                           struct ndisc_options *ndopts);
 137
 138 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 139                               int data_len, int pad);
 140
 141 #define NDISC_OPS_REDIRECT_DATA_SPACE   2
 142
 143 /*
 144  * This structure defines the hooks for IPv6 neighbour discovery.
 145  * The following hooks can be defined; unless noted otherwise, they are
 146  * optional and can be filled with a null pointer.
 147  *
 148  * int (*is_useropt)(u8 nd_opt_type):
 149  *     This function is called when IPv6 decide RA userspace options. if
 150  *     this function returns 1 then the option given by nd_opt_type will
 151  *     be handled as userspace option additional to the IPv6 options.
 152  *
 153  * int (*parse_options)(const struct net_device *dev,
 154  *                      struct nd_opt_hdr *nd_opt,
 155  *                      struct ndisc_options *ndopts):
 156  *     This function is called while parsing ndisc ops and put each position
 157  *     as pointer into ndopts. If this function return unequal 0, then this
 158  *     function took care about the ndisc option, if 0 then the IPv6 ndisc
 159  *     option parser will take care about that option.
 160  *
 161  * void (*update)(const struct net_device *dev, struct neighbour *n,
 162  *                u32 flags, u8 icmp6_type,
 163  *                const struct ndisc_options *ndopts):
 164  *     This function is called when IPv6 ndisc updates the neighbour cache
 165  *     entry. Additional options which can be updated may be previously
 166  *     parsed by parse_opts callback and accessible over ndopts parameter.
 167  *
 168  * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 169  *                       struct neighbour *neigh, u8 *ha_buf,
 170  *                       u8 **ha):
 171  *     This function is called when the necessary option space will be
 172  *     calculated before allocating a skb. The parameters neigh, ha_buf
 173  *     abd ha are available on NDISC_REDIRECT messages only.
 174  *
 175  * void (*fill_addr_option)(const struct net_device *dev,
 176  *                          struct sk_buff *skb, u8 icmp6_type,
 177  *                          const u8 *ha):
 178  *     This function is called when the skb will finally fill the option
 179  *     fields inside skb. NOTE: this callback should fill the option
 180  *     fields to the skb which are previously indicated by opt_space
 181  *     parameter. That means the decision to add such option should
 182  *     not lost between these two callbacks, e.g. protected by interface
 183  *     up state.
 184  *
 185  * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 186  *                             const struct prefix_info *pinfo,
 187  *                             struct inet6_dev *in6_dev,
 188  *                             struct in6_addr *addr,
 189  *                             int addr_type, u32 addr_flags,
 190  *                             bool sllao, bool tokenized,
 191  *                             __u32 valid_lft, u32 prefered_lft,
 192  *                             bool dev_addr_generated):
 193  *     This function is called when a RA messages is received with valid
 194  *     PIO option fields and an IPv6 address will be added to the interface
 195  *     for autoconfiguration. The parameter dev_addr_generated reports about
 196  *     if the address was based on dev->dev_addr or not. This can be used
 197  *     to add a second address if link-layer operates with two link layer
 198  *     addresses. E.g. 802.15.4 6LoWPAN.
 199  */
 200 struct ndisc_ops {
 201         int     (*is_useropt)(u8 nd_opt_type);
 202         int     (*parse_options)(const struct net_device *dev,
 203                                  struct nd_opt_hdr *nd_opt,
 204                                  struct ndisc_options *ndopts);
 205         void    (*update)(const struct net_device *dev, struct neighbour *n,
 206                           u32 flags, u8 icmp6_type,
 207                           const struct ndisc_options *ndopts);
 208         int     (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 209                                   struct neighbour *neigh, u8 *ha_buf,
 210                                   u8 **ha);
 211         void    (*fill_addr_option)(const struct net_device *dev,
 212                                     struct sk_buff *skb, u8 icmp6_type,
 213                                     const u8 *ha);
 214         void    (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 215                                        const struct prefix_info *pinfo,
 216                                        struct inet6_dev *in6_dev,
 217                                        struct in6_addr *addr,
 218                                        int addr_type, u32 addr_flags,
 219                                        bool sllao, bool tokenized,
 220                                        __u32 valid_lft, u32 prefered_lft,
 221                                        bool dev_addr_generated);
 222 };
 223
 224 #if IS_ENABLED(CONFIG_IPV6)
 225 static inline int ndisc_ops_is_useropt(const struct net_device *dev,
 226                                        u8 nd_opt_type)
 227 {
 228         if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
 229                 return dev->ndisc_ops->is_useropt(nd_opt_type);
 230         else
 231                 return 0;
 232 }
 233
 234 static inline int ndisc_ops_parse_options(const struct net_device *dev,
 235                                           struct nd_opt_hdr *nd_opt,
 236                                           struct ndisc_options *ndopts)
 237 {
 238         if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
 239                 return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
 240         else
 241                 return 0;
 242 }
 243
 244 static inline void ndisc_ops_update(const struct net_device *dev,
 245                                           struct neighbour *n, u32 flags,
 246                                           u8 icmp6_type,
 247                                           const struct ndisc_options *ndopts)
 248 {
 249         if (dev->ndisc_ops && dev->ndisc_ops->update)
 250                 dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
 251 }
 252
 253 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
 254                                            u8 icmp6_type)
 255 {
 256         if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
 257             icmp6_type != NDISC_REDIRECT)
 258                 return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
 259                                                       NULL, NULL);
 260         else
 261                 return 0;
 262 }
 263
 264 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
 265                                                     struct neighbour *neigh,
 266                                                     u8 *ha_buf, u8 **ha)
 267 {
 268         if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
 269                 return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
 270                                                       neigh, ha_buf, ha);
 271         else
 272                 return 0;
 273 }
 274
 275 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
 276                                               struct sk_buff *skb,
 277                                               u8 icmp6_type)
 278 {
 279         if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
 280             icmp6_type != NDISC_REDIRECT)
 281                 dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
 282 }
 283
 284 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
 285                                                        struct sk_buff *skb,
 286                                                        const u8 *ha)
 287 {
 288         if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
 289                 dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
 290 }
 291
 292 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
 293                                                  struct net_device *dev,
 294                                                  const struct prefix_info *pinfo,
 295                                                  struct inet6_dev *in6_dev,
 296                                                  struct in6_addr *addr,
 297                                                  int addr_type, u32 addr_flags,
 298                                                  bool sllao, bool tokenized,
 299                                                  __u32 valid_lft,
 300                                                  u32 prefered_lft,
 301                                                  bool dev_addr_generated)
 302 {
 303         if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
 304                 dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
 305                                                     addr, addr_type,
 306                                                     addr_flags, sllao,
 307                                                     tokenized, valid_lft,
 308                                                     prefered_lft,
 309                                                     dev_addr_generated);
 310 }
 311 #endif
 312
 313 /*
 314  * Return the padding between the option length and the start of the
 315  * link addr.  Currently only IP-over-InfiniBand needs this, although
 316  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 317  * also need a pad of 2.
 318  */
 319 static inline int ndisc_addr_option_pad(unsigned short type)
 320 {
 321         switch (type) {
 322         case ARPHRD_INFINIBAND: return 2;
 323         default:                return 0;
 324         }
 325 }
 326
 327 static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
 328 {
 329         return NDISC_OPT_SPACE(addr_len + pad);
 330 }
 331
 332 #if IS_ENABLED(CONFIG_IPV6)
 333 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
 334 {
 335         return __ndisc_opt_addr_space(dev->addr_len,
 336                                       ndisc_addr_option_pad(dev->type)) +
 337                 ndisc_ops_opt_addr_space(dev, icmp6_type);
 338 }
 339
 340 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
 341                                                 struct neighbour *neigh,
 342                                                 u8 *ops_data_buf,
 343                                                 u8 **ops_data)
 344 {
 345         return __ndisc_opt_addr_space(dev->addr_len,
 346                                       ndisc_addr_option_pad(dev->type)) +
 347                 ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
 348                                                   ops_data);
 349 }
 350 #endif
 351
 352 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
 353                                         unsigned char addr_len, int prepad)
 354 {
 355         u8 *lladdr = (u8 *)(p + 1);
 356         int lladdrlen = p->nd_opt_len << 3;
 357         if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
 358                 return NULL;
 359         return lladdr + prepad;
 360 }
 361
 362 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 363                                       struct net_device *dev)
 364 {
 365         return __ndisc_opt_addr_data(p, dev->addr_len,
 366                                      ndisc_addr_option_pad(dev->type));
 367 }
 368
 369 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
 370 {
 371         const u32 *p32 = pkey;
 372
 373         return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
 374                 (p32[1] * hash_rnd[1]) +
 375                 (p32[2] * hash_rnd[2]) +
 376                 (p32[3] * hash_rnd[3]));
 377 }
 378
 379 static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
 380 {
 381         return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
 382 }
 383
 384 static inline
 385 struct neighbour *__ipv6_neigh_lookup_noref_stub(struct net_device *dev,
 386                                                  const void *pkey)
 387 {
 388         return ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128,
 389                                      ndisc_hashfn, pkey, dev);
 390 }
 391
 392 static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
 393 {
 394         struct neighbour *n;
 395
 396         rcu_read_lock_bh();
 397         n = __ipv6_neigh_lookup_noref(dev, pkey);
 398         if (n && !refcount_inc_not_zero(&n->refcnt))
 399                 n = NULL;
 400         rcu_read_unlock_bh();
 401
 402         return n;
 403 }
 404
 405 static inline void __ipv6_confirm_neigh(struct net_device *dev,
 406                                         const void *pkey)
 407 {
 408         struct neighbour *n;
 409
 410         rcu_read_lock_bh();
 411         n = __ipv6_neigh_lookup_noref(dev, pkey);
 412         if (n) {
 413                 unsigned long now = jiffies;
 414
 415                 /* avoid dirtying neighbour */
 416                 if (n->confirmed != now)
 417                         n->confirmed = now;
 418         }
 419         rcu_read_unlock_bh();
 420 }
 421
 422 static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
 423                                              const void *pkey)
 424 {
 425         struct neighbour *n;
 426
 427         rcu_read_lock_bh();
 428         n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
 429         if (n) {
 430                 unsigned long now = jiffies;
 431
 432                 /* avoid dirtying neighbour */
 433                 if (n->confirmed != now)
 434                         n->confirmed = now;
 435         }
 436         rcu_read_unlock_bh();
 437 }
 438
 439 /* uses ipv6_stub and is meant for use outside of IPv6 core */
 440 static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
 441                                              const void *addr)
 442 {
 443         struct neighbour *neigh;
 444
 445         neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
 446         if (unlikely(!neigh))
 447                 neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
 448
 449         return neigh;
 450 }
 451
 452 int ndisc_init(void);
 453 int ndisc_late_init(void);
 454
 455 void ndisc_late_cleanup(void);
 456 void ndisc_cleanup(void);
 457
 458 int ndisc_rcv(struct sk_buff *skb);
 459
 460 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 461                    const struct in6_addr *daddr, const struct in6_addr *saddr,
 462                    u64 nonce);
 463
 464 void ndisc_send_rs(struct net_device *dev,
 465                    const struct in6_addr *saddr, const struct in6_addr *daddr);
 466 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 467                    const struct in6_addr *solicited_addr,
 468                    bool router, bool solicited, bool override, bool inc_opt);
 469
 470 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
 471
 472 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
 473                  int dir);
 474
 475 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 476                   const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 477                   struct ndisc_options *ndopts);
 478
 479 /*
 480  *      IGMP
 481  */
 482 int igmp6_init(void);
 483 int igmp6_late_init(void);
 484
 485 void igmp6_cleanup(void);
 486 void igmp6_late_cleanup(void);
 487
 488 int igmp6_event_query(struct sk_buff *skb);
 489
 490 int igmp6_event_report(struct sk_buff *skb);
 491
 492
 493 #ifdef CONFIG_SYSCTL
 494 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
 495                                void __user *buffer, size_t *lenp, loff_t *ppos);
 496 int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
 497                                  void __user *oldval, size_t __user *oldlenp,
 498                                  void __user *newval, size_t newlen);
 499 #endif
 500
 501 void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
 502
 503 #endif