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_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, ...)                         \
  65do {                                                            \
  66        if (val <= ND_DEBUG)                                    \
  67                net_##level##_ratelimited(fmt, ##__VA_ARGS__);  \
  68} while (0)
  69
  70struct ctl_table;
  71struct inet6_dev;
  72struct net_device;
  73struct net_proto_family;
  74struct sk_buff;
  75struct prefix_info;
  76
  77extern struct neigh_table nd_tbl;
  78
  79struct nd_msg {
  80        struct icmp6hdr icmph;
  81        struct in6_addr target;
  82        __u8            opt[0];
  83};
  84
  85struct rs_msg {
  86        struct icmp6hdr icmph;
  87        __u8            opt[0];
  88};
  89
  90struct ra_msg {
  91        struct icmp6hdr         icmph;
  92        __be32                  reachable_time;
  93        __be32                  retrans_timer;
  94};
  95
  96struct rd_msg {
  97        struct icmp6hdr icmph;
  98        struct in6_addr target;
  99        struct in6_addr dest;
 100        __u8            opt[0];
 101};
 102
 103struct nd_opt_hdr {
 104        __u8            nd_opt_type;
 105        __u8            nd_opt_len;
 106} __packed;
 107
 108/* ND options */
 109struct 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
 134struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 135                                          u8 *opt, int opt_len,
 136                                          struct ndisc_options *ndopts);
 137
 138void __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 */
 200struct 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)
 225static 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
 234static 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
 244static 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
 253static 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
 264static 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
 275static 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
 284static 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
 292static 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 */
 319static 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
 327static 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)
 333static 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
 340static 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
 352static 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
 362static 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
 369static 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
 379static 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
 384static inline
 385struct 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
 392static 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
 405static 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
 422static 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 */
 440static 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
 452int ndisc_init(void);
 453int ndisc_late_init(void);
 454
 455void ndisc_late_cleanup(void);
 456void ndisc_cleanup(void);
 457
 458int ndisc_rcv(struct sk_buff *skb);
 459
 460void 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
 464void ndisc_send_rs(struct net_device *dev,
 465                   const struct in6_addr *saddr, const struct in6_addr *daddr);
 466void 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
 470void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
 471
 472int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
 473                 int dir);
 474
 475void 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 */
 482int igmp6_init(void);
 483int igmp6_late_init(void);
 484
 485void igmp6_cleanup(void);
 486void igmp6_late_cleanup(void);
 487
 488int igmp6_event_query(struct sk_buff *skb);
 489
 490int igmp6_event_report(struct sk_buff *skb);
 491
 492
 493#ifdef CONFIG_SYSCTL
 494int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
 495                               void __user *buffer, size_t *lenp, loff_t *ppos);
 496int 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
 501void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
 502
 503#endif
 504