LXR linux/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
  30enum {
  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_CAPTIVE_PORTAL = 37,     /* RFC7710 */
  44        __ND_OPT_MAX
  45};
  46
  47#define MAX_RTR_SOLICITATION_DELAY      HZ
  48
  49#define ND_REACHABLE_TIME               (30*HZ)
  50#define ND_RETRANS_TIMER                HZ
  51
  52#include <linux/compiler.h>
  53#include <linux/icmpv6.h>
  54#include <linux/in6.h>
  55#include <linux/types.h>
  56#include <linux/if_arp.h>
  57#include <linux/netdevice.h>
  58#include <linux/hash.h>
  59
  60#include <net/neighbour.h>
  61
  62/* Set to 3 to get tracing... */
  63#define ND_DEBUG 1
  64
  65#define ND_PRINTK(val, level, fmt, ...)                         \
  66do {                                                            \
  67        if (val <= ND_DEBUG)                                    \
  68                net_##level##_ratelimited(fmt, ##__VA_ARGS__);  \
  69} while (0)
  70
  71struct ctl_table;
  72struct inet6_dev;
  73struct net_device;
  74struct net_proto_family;
  75struct sk_buff;
  76struct prefix_info;
  77
  78extern struct neigh_table nd_tbl;
  79
  80struct nd_msg {
  81        struct icmp6hdr icmph;
  82        struct in6_addr target;
  83        __u8            opt[0];
  84};
  85
  86struct rs_msg {
  87        struct icmp6hdr icmph;
  88        __u8            opt[0];
  89};
  90
  91struct ra_msg {
  92        struct icmp6hdr         icmph;
  93        __be32                  reachable_time;
  94        __be32                  retrans_timer;
  95};
  96
  97struct rd_msg {
  98        struct icmp6hdr icmph;
  99        struct in6_addr target;
 100        struct in6_addr dest;
 101        __u8            opt[0];
 102};
 103
 104struct nd_opt_hdr {
 105        __u8            nd_opt_type;
 106        __u8            nd_opt_len;
 107} __packed;
 108
 109/* ND options */
 110struct ndisc_options {
 111        struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 112#ifdef CONFIG_IPV6_ROUTE_INFO
 113        struct nd_opt_hdr *nd_opts_ri;
 114        struct nd_opt_hdr *nd_opts_ri_end;
 115#endif
 116        struct nd_opt_hdr *nd_useropts;
 117        struct nd_opt_hdr *nd_useropts_end;
 118#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 119        struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
 120#endif
 121};
 122
 123#define nd_opts_src_lladdr              nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
 124#define nd_opts_tgt_lladdr              nd_opt_array[ND_OPT_TARGET_LL_ADDR]
 125#define nd_opts_pi                      nd_opt_array[ND_OPT_PREFIX_INFO]
 126#define nd_opts_pi_end                  nd_opt_array[__ND_OPT_PREFIX_INFO_END]
 127#define nd_opts_rh                      nd_opt_array[ND_OPT_REDIRECT_HDR]
 128#define nd_opts_mtu                     nd_opt_array[ND_OPT_MTU]
 129#define nd_opts_nonce                   nd_opt_array[ND_OPT_NONCE]
 130#define nd_802154_opts_src_lladdr       nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
 131#define nd_802154_opts_tgt_lladdr       nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
 132
 133#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 134
 135struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 136                                          u8 *opt, int opt_len,
 137                                          struct ndisc_options *ndopts);
 138
 139void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 140                              int data_len, int pad);
 141
 142#define NDISC_OPS_REDIRECT_DATA_SPACE   2
 143
 144/*
 145 * This structure defines the hooks for IPv6 neighbour discovery.
 146 * The following hooks can be defined; unless noted otherwise, they are
 147 * optional and can be filled with a null pointer.
 148 *
 149 * int (*is_useropt)(u8 nd_opt_type):
 150 *     This function is called when IPv6 decide RA userspace options. if
 151 *     this function returns 1 then the option given by nd_opt_type will
 152 *     be handled as userspace option additional to the IPv6 options.
 153 *
 154 * int (*parse_options)(const struct net_device *dev,
 155 *                      struct nd_opt_hdr *nd_opt,
 156 *                      struct ndisc_options *ndopts):
 157 *     This function is called while parsing ndisc ops and put each position
 158 *     as pointer into ndopts. If this function return unequal 0, then this
 159 *     function took care about the ndisc option, if 0 then the IPv6 ndisc
 160 *     option parser will take care about that option.
 161 *
 162 * void (*update)(const struct net_device *dev, struct neighbour *n,
 163 *                u32 flags, u8 icmp6_type,
 164 *                const struct ndisc_options *ndopts):
 165 *     This function is called when IPv6 ndisc updates the neighbour cache
 166 *     entry. Additional options which can be updated may be previously
 167 *     parsed by parse_opts callback and accessible over ndopts parameter.
 168 *
 169 * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 170 *                       struct neighbour *neigh, u8 *ha_buf,
 171 *                       u8 **ha):
 172 *     This function is called when the necessary option space will be
 173 *     calculated before allocating a skb. The parameters neigh, ha_buf
 174 *     abd ha are available on NDISC_REDIRECT messages only.
 175 *
 176 * void (*fill_addr_option)(const struct net_device *dev,
 177 *                          struct sk_buff *skb, u8 icmp6_type,
 178 *                          const u8 *ha):
 179 *     This function is called when the skb will finally fill the option
 180 *     fields inside skb. NOTE: this callback should fill the option
 181 *     fields to the skb which are previously indicated by opt_space
 182 *     parameter. That means the decision to add such option should
 183 *     not lost between these two callbacks, e.g. protected by interface
 184 *     up state.
 185 *
 186 * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 187 *                             const struct prefix_info *pinfo,
 188 *                             struct inet6_dev *in6_dev,
 189 *                             struct in6_addr *addr,
 190 *                             int addr_type, u32 addr_flags,
 191 *                             bool sllao, bool tokenized,
 192 *                             __u32 valid_lft, u32 prefered_lft,
 193 *                             bool dev_addr_generated):
 194 *     This function is called when a RA messages is received with valid
 195 *     PIO option fields and an IPv6 address will be added to the interface
 196 *     for autoconfiguration. The parameter dev_addr_generated reports about
 197 *     if the address was based on dev->dev_addr or not. This can be used
 198 *     to add a second address if link-layer operates with two link layer
 199 *     addresses. E.g. 802.15.4 6LoWPAN.
 200 */
 201struct ndisc_ops {
 202        int     (*is_useropt)(u8 nd_opt_type);
 203        int     (*parse_options)(const struct net_device *dev,
 204                                 struct nd_opt_hdr *nd_opt,
 205                                 struct ndisc_options *ndopts);
 206        void    (*update)(const struct net_device *dev, struct neighbour *n,
 207                          u32 flags, u8 icmp6_type,
 208                          const struct ndisc_options *ndopts);
 209        int     (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 210                                  struct neighbour *neigh, u8 *ha_buf,
 211                                  u8 **ha);
 212        void    (*fill_addr_option)(const struct net_device *dev,
 213                                    struct sk_buff *skb, u8 icmp6_type,
 214                                    const u8 *ha);
 215        void    (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 216                                       const struct prefix_info *pinfo,
 217                                       struct inet6_dev *in6_dev,
 218                                       struct in6_addr *addr,
 219                                       int addr_type, u32 addr_flags,
 220                                       bool sllao, bool tokenized,
 221                                       __u32 valid_lft, u32 prefered_lft,
 222                                       bool dev_addr_generated);
 223};
 224
 225#if IS_ENABLED(CONFIG_IPV6)
 226static inline int ndisc_ops_is_useropt(const struct net_device *dev,
 227                                       u8 nd_opt_type)
 228{
 229        if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
 230                return dev->ndisc_ops->is_useropt(nd_opt_type);
 231        else
 232                return 0;
 233}
 234
 235static inline int ndisc_ops_parse_options(const struct net_device *dev,
 236                                          struct nd_opt_hdr *nd_opt,
 237                                          struct ndisc_options *ndopts)
 238{
 239        if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
 240                return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
 241        else
 242                return 0;
 243}
 244
 245static inline void ndisc_ops_update(const struct net_device *dev,
 246                                          struct neighbour *n, u32 flags,
 247                                          u8 icmp6_type,
 248                                          const struct ndisc_options *ndopts)
 249{
 250        if (dev->ndisc_ops && dev->ndisc_ops->update)
 251                dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
 252}
 253
 254static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
 255                                           u8 icmp6_type)
 256{
 257        if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
 258            icmp6_type != NDISC_REDIRECT)
 259                return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
 260                                                      NULL, NULL);
 261        else
 262                return 0;
 263}
 264
 265static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
 266                                                    struct neighbour *neigh,
 267                                                    u8 *ha_buf, u8 **ha)
 268{
 269        if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
 270                return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
 271                                                      neigh, ha_buf, ha);
 272        else
 273                return 0;
 274}
 275
 276static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
 277                                              struct sk_buff *skb,
 278                                              u8 icmp6_type)
 279{
 280        if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
 281            icmp6_type != NDISC_REDIRECT)
 282                dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
 283}
 284
 285static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
 286                                                       struct sk_buff *skb,
 287                                                       const u8 *ha)
 288{
 289        if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
 290                dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
 291}
 292
 293static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
 294                                                 struct net_device *dev,
 295                                                 const struct prefix_info *pinfo,
 296                                                 struct inet6_dev *in6_dev,
 297                                                 struct in6_addr *addr,
 298                                                 int addr_type, u32 addr_flags,
 299                                                 bool sllao, bool tokenized,
 300                                                 __u32 valid_lft,
 301                                                 u32 prefered_lft,
 302                                                 bool dev_addr_generated)
 303{
 304        if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
 305                dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
 306                                                    addr, addr_type,
 307                                                    addr_flags, sllao,
 308                                                    tokenized, valid_lft,
 309                                                    prefered_lft,
 310                                                    dev_addr_generated);
 311}
 312#endif
 313
 314/*
 315 * Return the padding between the option length and the start of the
 316 * link addr.  Currently only IP-over-InfiniBand needs this, although
 317 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 318 * also need a pad of 2.
 319 */
 320static inline int ndisc_addr_option_pad(unsigned short type)
 321{
 322        switch (type) {
 323        case ARPHRD_INFINIBAND: return 2;
 324        default:                return 0;
 325        }
 326}
 327
 328static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
 329{
 330        return NDISC_OPT_SPACE(addr_len + pad);
 331}
 332
 333#if IS_ENABLED(CONFIG_IPV6)
 334static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
 335{
 336        return __ndisc_opt_addr_space(dev->addr_len,
 337                                      ndisc_addr_option_pad(dev->type)) +
 338                ndisc_ops_opt_addr_space(dev, icmp6_type);
 339}
 340
 341static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
 342                                                struct neighbour *neigh,
 343                                                u8 *ops_data_buf,
 344                                                u8 **ops_data)
 345{
 346        return __ndisc_opt_addr_space(dev->addr_len,
 347                                      ndisc_addr_option_pad(dev->type)) +
 348                ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
 349                                                  ops_data);
 350}
 351#endif
 352
 353static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
 354                                        unsigned char addr_len, int prepad)
 355{
 356        u8 *lladdr = (u8 *)(p + 1);
 357        int lladdrlen = p->nd_opt_len << 3;
 358        if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
 359                return NULL;
 360        return lladdr + prepad;
 361}
 362
 363static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 364                                      struct net_device *dev)
 365{
 366        return __ndisc_opt_addr_data(p, dev->addr_len,
 367                                     ndisc_addr_option_pad(dev->type));
 368}
 369
 370static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
 371{
 372        const u32 *p32 = pkey;
 373
 374        return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
 375                (p32[1] * hash_rnd[1]) +
 376                (p32[2] * hash_rnd[2]) +
 377                (p32[3] * hash_rnd[3]));
 378}
 379
 380static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
 381{
 382        return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
 383}
 384
 385static inline
 386struct neighbour *__ipv6_neigh_lookup_noref_stub(struct net_device *dev,
 387                                                 const void *pkey)
 388{
 389        return ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128,
 390                                     ndisc_hashfn, pkey, dev);
 391}
 392
 393static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
 394{
 395        struct neighbour *n;
 396
 397        rcu_read_lock_bh();
 398        n = __ipv6_neigh_lookup_noref(dev, pkey);
 399        if (n && !refcount_inc_not_zero(&n->refcnt))
 400                n = NULL;
 401        rcu_read_unlock_bh();
 402
 403        return n;
 404}
 405
 406static inline void __ipv6_confirm_neigh(struct net_device *dev,
 407                                        const void *pkey)
 408{
 409        struct neighbour *n;
 410
 411        rcu_read_lock_bh();
 412        n = __ipv6_neigh_lookup_noref(dev, pkey);
 413        if (n) {
 414                unsigned long now = jiffies;
 415
 416                /* avoid dirtying neighbour */
 417                if (n->confirmed != now)
 418                        n->confirmed = now;
 419        }
 420        rcu_read_unlock_bh();
 421}
 422
 423static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
 424                                             const void *pkey)
 425{
 426        struct neighbour *n;
 427
 428        rcu_read_lock_bh();
 429        n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
 430        if (n) {
 431                unsigned long now = jiffies;
 432
 433                /* avoid dirtying neighbour */
 434                if (n->confirmed != now)
 435                        n->confirmed = now;
 436        }
 437        rcu_read_unlock_bh();
 438}
 439
 440/* uses ipv6_stub and is meant for use outside of IPv6 core */
 441static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
 442                                             const void *addr)
 443{
 444        struct neighbour *neigh;
 445
 446        neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
 447        if (unlikely(!neigh))
 448                neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
 449
 450        return neigh;
 451}
 452
 453int ndisc_init(void);
 454int ndisc_late_init(void);
 455
 456void ndisc_late_cleanup(void);
 457void ndisc_cleanup(void);
 458
 459int ndisc_rcv(struct sk_buff *skb);
 460
 461void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 462                   const struct in6_addr *daddr, const struct in6_addr *saddr,
 463                   u64 nonce);
 464
 465void ndisc_send_rs(struct net_device *dev,
 466                   const struct in6_addr *saddr, const struct in6_addr *daddr);
 467void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 468                   const struct in6_addr *solicited_addr,
 469                   bool router, bool solicited, bool override, bool inc_opt);
 470
 471void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
 472
 473int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
 474                 int dir);
 475
 476void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 477                  const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 478                  struct ndisc_options *ndopts);
 479
 480/*
 481 *      IGMP
 482 */
 483int igmp6_init(void);
 484int igmp6_late_init(void);
 485
 486void igmp6_cleanup(void);
 487void igmp6_late_cleanup(void);
 488
 489int igmp6_event_query(struct sk_buff *skb);
 490
 491int igmp6_event_report(struct sk_buff *skb);
 492
 493
 494#ifdef CONFIG_SYSCTL
 495int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
 496                               void __user *buffer, size_t *lenp, loff_t *ppos);
 497int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
 498                                 void __user *oldval, size_t __user *oldlenp,
 499                                 void __user *newval, size_t newlen);
 500#endif
 501
 502void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
 503
 504#endif
 505