LXR linux/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
  28enum {
  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, ...)                         \
  63do {                                                            \
  64        if (val <= ND_DEBUG)                                    \
  65                net_##level##_ratelimited(fmt, ##__VA_ARGS__);  \
  66} while (0)
  67
  68struct ctl_table;
  69struct inet6_dev;
  70struct net_device;
  71struct net_proto_family;
  72struct sk_buff;
  73struct prefix_info;
  74
  75extern struct neigh_table nd_tbl;
  76
  77struct nd_msg {
  78        struct icmp6hdr icmph;
  79        struct in6_addr target;
  80        __u8            opt[0];
  81};
  82
  83struct rs_msg {
  84        struct icmp6hdr icmph;
  85        __u8            opt[0];
  86};
  87
  88struct ra_msg {
  89        struct icmp6hdr         icmph;
  90        __be32                  reachable_time;
  91        __be32                  retrans_timer;
  92};
  93
  94struct rd_msg {
  95        struct icmp6hdr icmph;
  96        struct in6_addr target;
  97        struct in6_addr dest;
  98        __u8            opt[0];
  99};
 100
 101struct nd_opt_hdr {
 102        __u8            nd_opt_type;
 103        __u8            nd_opt_len;
 104} __packed;
 105
 106/* ND options */
 107struct 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
 132struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 133                                          u8 *opt, int opt_len,
 134                                          struct ndisc_options *ndopts);
 135
 136void __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 */
 198struct 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)
 223static 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
 232static 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
 242static 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
 251static 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
 262static 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
 273static 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
 282static 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
 290static 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 */
 317static 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
 325static 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)
 331static 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
 338static 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
 350static 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
 360static 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
 367static 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
 377static 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
 382static 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
 395static 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
 412int ndisc_init(void);
 413int ndisc_late_init(void);
 414
 415void ndisc_late_cleanup(void);
 416void ndisc_cleanup(void);
 417
 418int ndisc_rcv(struct sk_buff *skb);
 419
 420void 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
 424void ndisc_send_rs(struct net_device *dev,
 425                   const struct in6_addr *saddr, const struct in6_addr *daddr);
 426void 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
 430void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
 431
 432int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
 433                 int dir);
 434
 435void 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 */
 442int igmp6_init(void);
 443int igmp6_late_init(void);
 444
 445void igmp6_cleanup(void);
 446void igmp6_late_cleanup(void);
 447
 448int igmp6_event_query(struct sk_buff *skb);
 449
 450int igmp6_event_report(struct sk_buff *skb);
 451
 452
 453#ifdef CONFIG_SYSCTL
 454int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
 455                               void __user *buffer, size_t *lenp, loff_t *ppos);
 456int 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
 461void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
 462
 463#endif
 464