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_PREF64 = 38,             /* RFC8781 */
  45        __ND_OPT_MAX
  46};
  47
  48#define MAX_RTR_SOLICITATION_DELAY      HZ
  49
  50#define ND_REACHABLE_TIME               (30*HZ)
  51#define ND_RETRANS_TIMER                HZ
  52
  53#include <linux/compiler.h>
  54#include <linux/icmpv6.h>
  55#include <linux/in6.h>
  56#include <linux/types.h>
  57#include <linux/if_arp.h>
  58#include <linux/netdevice.h>
  59#include <linux/hash.h>
  60
  61#include <net/neighbour.h>
  62
  63/* Set to 3 to get tracing... */
  64#define ND_DEBUG 1
  65
  66#define ND_PRINTK(val, level, fmt, ...)                         \
  67do {                                                            \
  68        if (val <= ND_DEBUG)                                    \
  69                net_##level##_ratelimited(fmt, ##__VA_ARGS__);  \
  70} while (0)
  71
  72struct ctl_table;
  73struct inet6_dev;
  74struct net_device;
  75struct net_proto_family;
  76struct sk_buff;
  77struct prefix_info;
  78
  79extern struct neigh_table nd_tbl;
  80
  81struct nd_msg {
  82        struct icmp6hdr icmph;
  83        struct in6_addr target;
  84        __u8            opt[];
  85};
  86
  87struct rs_msg {
  88        struct icmp6hdr icmph;
  89        __u8            opt[];
  90};
  91
  92struct ra_msg {
  93        struct icmp6hdr         icmph;
  94        __be32                  reachable_time;
  95        __be32                  retrans_timer;
  96};
  97
  98struct rd_msg {
  99        struct icmp6hdr icmph;
 100        struct in6_addr target;
 101        struct in6_addr dest;
 102        __u8            opt[];
 103};
 104
 105struct nd_opt_hdr {
 106        __u8            nd_opt_type;
 107        __u8            nd_opt_len;
 108} __packed;
 109
 110/* ND options */
 111struct ndisc_options {
 112        struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 113#ifdef CONFIG_IPV6_ROUTE_INFO
 114        struct nd_opt_hdr *nd_opts_ri;
 115        struct nd_opt_hdr *nd_opts_ri_end;
 116#endif
 117        struct nd_opt_hdr *nd_useropts;
 118        struct nd_opt_hdr *nd_useropts_end;
 119#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 120        struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
 121#endif
 122};
 123
 124#define nd_opts_src_lladdr              nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
 125#define nd_opts_tgt_lladdr              nd_opt_array[ND_OPT_TARGET_LL_ADDR]
 126#define nd_opts_pi                      nd_opt_array[ND_OPT_PREFIX_INFO]
 127#define nd_opts_pi_end                  nd_opt_array[__ND_OPT_PREFIX_INFO_END]
 128#define nd_opts_rh                      nd_opt_array[ND_OPT_REDIRECT_HDR]
 129#define nd_opts_mtu                     nd_opt_array[ND_OPT_MTU]
 130#define nd_opts_nonce                   nd_opt_array[ND_OPT_NONCE]
 131#define nd_802154_opts_src_lladdr       nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
 132#define nd_802154_opts_tgt_lladdr       nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
 133
 134#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 135
 136struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 137                                          u8 *opt, int opt_len,
 138                                          struct ndisc_options *ndopts);
 139
 140void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 141                              int data_len, int pad);
 142
 143#define NDISC_OPS_REDIRECT_DATA_SPACE   2
 144
 145/*
 146 * This structure defines the hooks for IPv6 neighbour discovery.
 147 * The following hooks can be defined; unless noted otherwise, they are
 148 * optional and can be filled with a null pointer.
 149 *
 150 * int (*is_useropt)(u8 nd_opt_type):
 151 *     This function is called when IPv6 decide RA userspace options. if
 152 *     this function returns 1 then the option given by nd_opt_type will
 153 *     be handled as userspace option additional to the IPv6 options.
 154 *
 155 * int (*parse_options)(const struct net_device *dev,
 156 *                      struct nd_opt_hdr *nd_opt,
 157 *                      struct ndisc_options *ndopts):
 158 *     This function is called while parsing ndisc ops and put each position
 159 *     as pointer into ndopts. If this function return unequal 0, then this
 160 *     function took care about the ndisc option, if 0 then the IPv6 ndisc
 161 *     option parser will take care about that option.
 162 *
 163 * void (*update)(const struct net_device *dev, struct neighbour *n,
 164 *                u32 flags, u8 icmp6_type,
 165 *                const struct ndisc_options *ndopts):
 166 *     This function is called when IPv6 ndisc updates the neighbour cache
 167 *     entry. Additional options which can be updated may be previously
 168 *     parsed by parse_opts callback and accessible over ndopts parameter.
 169 *
 170 * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 171 *                       struct neighbour *neigh, u8 *ha_buf,
 172 *                       u8 **ha):
 173 *     This function is called when the necessary option space will be
 174 *     calculated before allocating a skb. The parameters neigh, ha_buf
 175 *     abd ha are available on NDISC_REDIRECT messages only.
 176 *
 177 * void (*fill_addr_option)(const struct net_device *dev,
 178 *                          struct sk_buff *skb, u8 icmp6_type,
 179 *                          const u8 *ha):
 180 *     This function is called when the skb will finally fill the option
 181 *     fields inside skb. NOTE: this callback should fill the option
 182 *     fields to the skb which are previously indicated by opt_space
 183 *     parameter. That means the decision to add such option should
 184 *     not lost between these two callbacks, e.g. protected by interface
 185 *     up state.
 186 *
 187 * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 188 *                             const struct prefix_info *pinfo,
 189 *                             struct inet6_dev *in6_dev,
 190 *                             struct in6_addr *addr,
 191 *                             int addr_type, u32 addr_flags,
 192 *                             bool sllao, bool tokenized,
 193 *                             __u32 valid_lft, u32 prefered_lft,
 194 *                             bool dev_addr_generated):
 195 *     This function is called when a RA messages is received with valid
 196 *     PIO option fields and an IPv6 address will be added to the interface
 197 *     for autoconfiguration. The parameter dev_addr_generated reports about
 198 *     if the address was based on dev->dev_addr or not. This can be used
 199 *     to add a second address if link-layer operates with two link layer
 200 *     addresses. E.g. 802.15.4 6LoWPAN.
 201 */
 202struct ndisc_ops {
 203        int     (*is_useropt)(u8 nd_opt_type);
 204        int     (*parse_options)(const struct net_device *dev,
 205                                 struct nd_opt_hdr *nd_opt,
 206                                 struct ndisc_options *ndopts);
 207        void    (*update)(const struct net_device *dev, struct neighbour *n,
 208                          u32 flags, u8 icmp6_type,
 209                          const struct ndisc_options *ndopts);
 210        int     (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 211                                  struct neighbour *neigh, u8 *ha_buf,
 212                                  u8 **ha);
 213        void    (*fill_addr_option)(const struct net_device *dev,
 214                                    struct sk_buff *skb, u8 icmp6_type,
 215                                    const u8 *ha);
 216        void    (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 217                                       const struct prefix_info *pinfo,
 218                                       struct inet6_dev *in6_dev,
 219                                       struct in6_addr *addr,
 220                                       int addr_type, u32 addr_flags,
 221                                       bool sllao, bool tokenized,
 222                                       __u32 valid_lft, u32 prefered_lft,
 223                                       bool dev_addr_generated);
 224};
 225
 226#if IS_ENABLED(CONFIG_IPV6)
 227static inline int ndisc_ops_is_useropt(const struct net_device *dev,
 228                                       u8 nd_opt_type)
 229{
 230        if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
 231                return dev->ndisc_ops->is_useropt(nd_opt_type);
 232        else
 233                return 0;
 234}
 235
 236static inline int ndisc_ops_parse_options(const struct net_device *dev,
 237                                          struct nd_opt_hdr *nd_opt,
 238                                          struct ndisc_options *ndopts)
 239{
 240        if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
 241                return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
 242        else
 243                return 0;
 244}
 245
 246static inline void ndisc_ops_update(const struct net_device *dev,
 247                                          struct neighbour *n, u32 flags,
 248                                          u8 icmp6_type,
 249                                          const struct ndisc_options *ndopts)
 250{
 251        if (dev->ndisc_ops && dev->ndisc_ops->update)
 252                dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
 253}
 254
 255static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
 256                                           u8 icmp6_type)
 257{
 258        if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
 259            icmp6_type != NDISC_REDIRECT)
 260                return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
 261                                                      NULL, NULL);
 262        else
 263                return 0;
 264}
 265
 266static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
 267                                                    struct neighbour *neigh,
 268                                                    u8 *ha_buf, u8 **ha)
 269{
 270        if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
 271                return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
 272                                                      neigh, ha_buf, ha);
 273        else
 274                return 0;
 275}
 276
 277static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
 278                                              struct sk_buff *skb,
 279                                              u8 icmp6_type)
 280{
 281        if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
 282            icmp6_type != NDISC_REDIRECT)
 283                dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
 284}
 285
 286static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
 287                                                       struct sk_buff *skb,
 288                                                       const u8 *ha)
 289{
 290        if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
 291                dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
 292}
 293
 294static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
 295                                                 struct net_device *dev,
 296                                                 const struct prefix_info *pinfo,
 297                                                 struct inet6_dev *in6_dev,
 298                                                 struct in6_addr *addr,
 299                                                 int addr_type, u32 addr_flags,
 300                                                 bool sllao, bool tokenized,
 301                                                 __u32 valid_lft,
 302                                                 u32 prefered_lft,
 303                                                 bool dev_addr_generated)
 304{
 305        if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
 306                dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
 307                                                    addr, addr_type,
 308                                                    addr_flags, sllao,
 309                                                    tokenized, valid_lft,
 310                                                    prefered_lft,
 311                                                    dev_addr_generated);
 312}
 313#endif
 314
 315/*
 316 * Return the padding between the option length and the start of the
 317 * link addr.  Currently only IP-over-InfiniBand needs this, although
 318 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 319 * also need a pad of 2.
 320 */
 321static inline int ndisc_addr_option_pad(unsigned short type)
 322{
 323        switch (type) {
 324        case ARPHRD_INFINIBAND: return 2;
 325        default:                return 0;
 326        }
 327}
 328
 329static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
 330{
 331        return NDISC_OPT_SPACE(addr_len + pad);
 332}
 333
 334#if IS_ENABLED(CONFIG_IPV6)
 335static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
 336{
 337        return __ndisc_opt_addr_space(dev->addr_len,
 338                                      ndisc_addr_option_pad(dev->type)) +
 339                ndisc_ops_opt_addr_space(dev, icmp6_type);
 340}
 341
 342static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
 343                                                struct neighbour *neigh,
 344                                                u8 *ops_data_buf,
 345                                                u8 **ops_data)
 346{
 347        return __ndisc_opt_addr_space(dev->addr_len,
 348                                      ndisc_addr_option_pad(dev->type)) +
 349                ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
 350                                                  ops_data);
 351}
 352#endif
 353
 354static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
 355                                        unsigned char addr_len, int prepad)
 356{
 357        u8 *lladdr = (u8 *)(p + 1);
 358        int lladdrlen = p->nd_opt_len << 3;
 359        if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
 360                return NULL;
 361        return lladdr + prepad;
 362}
 363
 364static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 365                                      struct net_device *dev)
 366{
 367        return __ndisc_opt_addr_data(p, dev->addr_len,
 368                                     ndisc_addr_option_pad(dev->type));
 369}
 370
 371static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
 372{
 373        const u32 *p32 = pkey;
 374
 375        return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
 376                (p32[1] * hash_rnd[1]) +
 377                (p32[2] * hash_rnd[2]) +
 378                (p32[3] * hash_rnd[3]));
 379}
 380
 381static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
 382{
 383        return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
 384}
 385
 386static inline
 387struct neighbour *__ipv6_neigh_lookup_noref_stub(struct net_device *dev,
 388                                                 const void *pkey)
 389{
 390        return ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128,
 391                                     ndisc_hashfn, pkey, dev);
 392}
 393
 394static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
 395{
 396        struct neighbour *n;
 397
 398        rcu_read_lock_bh();
 399        n = __ipv6_neigh_lookup_noref(dev, pkey);
 400        if (n && !refcount_inc_not_zero(&n->refcnt))
 401                n = NULL;
 402        rcu_read_unlock_bh();
 403
 404        return n;
 405}
 406
 407static inline void __ipv6_confirm_neigh(struct net_device *dev,
 408                                        const void *pkey)
 409{
 410        struct neighbour *n;
 411
 412        rcu_read_lock_bh();
 413        n = __ipv6_neigh_lookup_noref(dev, pkey);
 414        if (n) {
 415                unsigned long now = jiffies;
 416
 417                /* avoid dirtying neighbour */
 418                if (READ_ONCE(n->confirmed) != now)
 419                        WRITE_ONCE(n->confirmed, now);
 420        }
 421        rcu_read_unlock_bh();
 422}
 423
 424static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
 425                                             const void *pkey)
 426{
 427        struct neighbour *n;
 428
 429        rcu_read_lock_bh();
 430        n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
 431        if (n) {
 432                unsigned long now = jiffies;
 433
 434                /* avoid dirtying neighbour */
 435                if (READ_ONCE(n->confirmed) != now)
 436                        WRITE_ONCE(n->confirmed, now);
 437        }
 438        rcu_read_unlock_bh();
 439}
 440
 441/* uses ipv6_stub and is meant for use outside of IPv6 core */
 442static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
 443                                             const void *addr)
 444{
 445        struct neighbour *neigh;
 446
 447        neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
 448        if (unlikely(!neigh))
 449                neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
 450
 451        return neigh;
 452}
 453
 454int ndisc_init(void);
 455int ndisc_late_init(void);
 456
 457void ndisc_late_cleanup(void);
 458void ndisc_cleanup(void);
 459
 460int ndisc_rcv(struct sk_buff *skb);
 461
 462void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 463                   const struct in6_addr *daddr, const struct in6_addr *saddr,
 464                   u64 nonce);
 465
 466void ndisc_send_rs(struct net_device *dev,
 467                   const struct in6_addr *saddr, const struct in6_addr *daddr);
 468void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 469                   const struct in6_addr *solicited_addr,
 470                   bool router, bool solicited, bool override, bool inc_opt);
 471
 472void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
 473
 474int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
 475                 int dir);
 476
 477void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 478                  const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 479                  struct ndisc_options *ndopts);
 480
 481/*
 482 *      IGMP
 483 */
 484int igmp6_init(void);
 485int igmp6_late_init(void);
 486
 487void igmp6_cleanup(void);
 488void igmp6_late_cleanup(void);
 489
 490int igmp6_event_query(struct sk_buff *skb);
 491
 492int igmp6_event_report(struct sk_buff *skb);
 493
 494
 495#ifdef CONFIG_SYSCTL
 496int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
 497                               void *buffer, size_t *lenp, loff_t *ppos);
 498int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
 499                                 void __user *oldval, size_t __user *oldlenp,
 500                                 void __user *newval, size_t newlen);
 501#endif
 502
 503void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
 504
 505#endif
 506