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 28 enum { 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_CAPTIVE_PORTAL = 37, /* RFC7710 */ 42 ND_OPT_PREF64 = 38, /* RFC8781 */ 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 struct ctl_table; 62 struct inet6_dev; 63 struct net_device; 64 struct net_proto_family; 65 struct sk_buff; 66 struct prefix_info; 67 68 extern struct neigh_table nd_tbl; 69 70 static inline struct neigh_table *nd_table(struct net *net) 71 { 72 #if IS_ENABLED(CONFIG_IPV6) 73 if (disable_ipv6_mod) 74 return &nd_tbl; 75 #endif 76 return net->neigh_tables[NEIGH_ND_TABLE]; 77 } 78 79 struct nd_msg { 80 struct icmp6hdr icmph; 81 struct in6_addr target; 82 __u8 opt[]; 83 }; 84 85 struct rs_msg { 86 struct icmp6hdr icmph; 87 __u8 opt[]; 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[]; 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, const 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 (*parse_options)(const struct net_device *dev, 149 * struct nd_opt_hdr *nd_opt, 150 * struct ndisc_options *ndopts): 151 * This function is called while parsing ndisc ops and put each position 152 * as pointer into ndopts. If this function return unequal 0, then this 153 * function took care about the ndisc option, if 0 then the IPv6 ndisc 154 * option parser will take care about that option. 155 * 156 * void (*update)(const struct net_device *dev, struct neighbour *n, 157 * u32 flags, u8 icmp6_type, 158 * const struct ndisc_options *ndopts): 159 * This function is called when IPv6 ndisc updates the neighbour cache 160 * entry. Additional options which can be updated may be previously 161 * parsed by parse_opts callback and accessible over ndopts parameter. 162 * 163 * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type, 164 * struct neighbour *neigh, u8 *ha_buf, 165 * u8 **ha): 166 * This function is called when the necessary option space will be 167 * calculated before allocating a skb. The parameters neigh, ha_buf 168 * abd ha are available on NDISC_REDIRECT messages only. 169 * 170 * void (*fill_addr_option)(const struct net_device *dev, 171 * struct sk_buff *skb, u8 icmp6_type, 172 * const u8 *ha): 173 * This function is called when the skb will finally fill the option 174 * fields inside skb. NOTE: this callback should fill the option 175 * fields to the skb which are previously indicated by opt_space 176 * parameter. That means the decision to add such option should 177 * not lost between these two callbacks, e.g. protected by interface 178 * up state. 179 * 180 * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev, 181 * const struct prefix_info *pinfo, 182 * struct inet6_dev *in6_dev, 183 * struct in6_addr *addr, 184 * int addr_type, u32 addr_flags, 185 * bool sllao, bool tokenized, 186 * __u32 valid_lft, u32 prefered_lft, 187 * bool dev_addr_generated): 188 * This function is called when a RA messages is received with valid 189 * PIO option fields and an IPv6 address will be added to the interface 190 * for autoconfiguration. The parameter dev_addr_generated reports about 191 * if the address was based on dev->dev_addr or not. This can be used 192 * to add a second address if link-layer operates with two link layer 193 * addresses. E.g. 802.15.4 6LoWPAN. 194 */ 195 struct ndisc_ops { 196 int (*parse_options)(const struct net_device *dev, 197 struct nd_opt_hdr *nd_opt, 198 struct ndisc_options *ndopts); 199 void (*update)(const struct net_device *dev, struct neighbour *n, 200 u32 flags, u8 icmp6_type, 201 const struct ndisc_options *ndopts); 202 int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type, 203 struct neighbour *neigh, u8 *ha_buf, 204 u8 **ha); 205 void (*fill_addr_option)(const struct net_device *dev, 206 struct sk_buff *skb, u8 icmp6_type, 207 const u8 *ha); 208 void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev, 209 const struct prefix_info *pinfo, 210 struct inet6_dev *in6_dev, 211 struct in6_addr *addr, 212 int addr_type, u32 addr_flags, 213 bool sllao, bool tokenized, 214 __u32 valid_lft, u32 prefered_lft, 215 bool dev_addr_generated); 216 }; 217 218 #if IS_ENABLED(CONFIG_IPV6) 219 static inline int ndisc_ops_parse_options(const struct net_device *dev, 220 struct nd_opt_hdr *nd_opt, 221 struct ndisc_options *ndopts) 222 { 223 if (dev->ndisc_ops && dev->ndisc_ops->parse_options) 224 return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts); 225 else 226 return 0; 227 } 228 229 static inline void ndisc_ops_update(const struct net_device *dev, 230 struct neighbour *n, u32 flags, 231 u8 icmp6_type, 232 const struct ndisc_options *ndopts) 233 { 234 if (dev->ndisc_ops && dev->ndisc_ops->update) 235 dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts); 236 } 237 238 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev, 239 u8 icmp6_type) 240 { 241 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space && 242 icmp6_type != NDISC_REDIRECT) 243 return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL, 244 NULL, NULL); 245 else 246 return 0; 247 } 248 249 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev, 250 struct neighbour *neigh, 251 u8 *ha_buf, u8 **ha) 252 { 253 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space) 254 return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT, 255 neigh, ha_buf, ha); 256 else 257 return 0; 258 } 259 260 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev, 261 struct sk_buff *skb, 262 u8 icmp6_type) 263 { 264 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option && 265 icmp6_type != NDISC_REDIRECT) 266 dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL); 267 } 268 269 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev, 270 struct sk_buff *skb, 271 const u8 *ha) 272 { 273 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option) 274 dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha); 275 } 276 277 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net, 278 struct net_device *dev, 279 const struct prefix_info *pinfo, 280 struct inet6_dev *in6_dev, 281 struct in6_addr *addr, 282 int addr_type, u32 addr_flags, 283 bool sllao, bool tokenized, 284 __u32 valid_lft, 285 u32 prefered_lft, 286 bool dev_addr_generated) 287 { 288 if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr) 289 dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev, 290 addr, addr_type, 291 addr_flags, sllao, 292 tokenized, valid_lft, 293 prefered_lft, 294 dev_addr_generated); 295 } 296 #endif 297 298 /* 299 * Return the padding between the option length and the start of the 300 * link addr. Currently only IP-over-InfiniBand needs this, although 301 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may 302 * also need a pad of 2. 303 */ 304 static inline int ndisc_addr_option_pad(unsigned short type) 305 { 306 switch (type) { 307 case ARPHRD_INFINIBAND: return 2; 308 default: return 0; 309 } 310 } 311 312 static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad) 313 { 314 return NDISC_OPT_SPACE(addr_len + pad); 315 } 316 317 #if IS_ENABLED(CONFIG_IPV6) 318 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type) 319 { 320 return __ndisc_opt_addr_space(dev->addr_len, 321 ndisc_addr_option_pad(dev->type)) + 322 ndisc_ops_opt_addr_space(dev, icmp6_type); 323 } 324 325 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev, 326 struct neighbour *neigh, 327 u8 *ops_data_buf, 328 u8 **ops_data) 329 { 330 return __ndisc_opt_addr_space(dev->addr_len, 331 ndisc_addr_option_pad(dev->type)) + 332 ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf, 333 ops_data); 334 } 335 #endif 336 337 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p, 338 unsigned char addr_len, int prepad) 339 { 340 u8 *lladdr = (u8 *)(p + 1); 341 int lladdrlen = p->nd_opt_len << 3; 342 if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad)) 343 return NULL; 344 return lladdr + prepad; 345 } 346 347 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p, 348 struct net_device *dev) 349 { 350 return __ndisc_opt_addr_data(p, dev->addr_len, 351 ndisc_addr_option_pad(dev->type)); 352 } 353 354 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd) 355 { 356 const u32 *p32 = pkey; 357 358 return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) + 359 (p32[1] * hash_rnd[1]) + 360 (p32[2] * hash_rnd[2]) + 361 (p32[3] * hash_rnd[3])); 362 } 363 364 static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey) 365 { 366 struct neigh_table *tbl = nd_table(dev_net(dev)); 367 368 return ___neigh_lookup_noref(tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev); 369 } 370 371 static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey) 372 { 373 struct neighbour *n; 374 375 rcu_read_lock(); 376 n = __ipv6_neigh_lookup_noref(dev, pkey); 377 if (n && !refcount_inc_not_zero(&n->refcnt)) 378 n = NULL; 379 rcu_read_unlock(); 380 381 return n; 382 } 383 384 static inline struct neighbour *ipv6_neigh_lookup(struct net_device *dev, 385 const void *pkey) 386 { 387 struct neigh_table *tbl = nd_table(dev_net(dev)); 388 389 return neigh_lookup(tbl, pkey, dev); 390 } 391 392 static inline struct neighbour *ipv6_neigh_create(struct net_device *dev, 393 const void *pkey) 394 { 395 struct neigh_table *tbl = nd_table(dev_net(dev)); 396 397 return neigh_create(tbl, pkey, dev); 398 } 399 400 static inline struct neighbour *ipv6_neigh_create_noref(struct net_device *dev, 401 const void *pkey) 402 { 403 struct neigh_table *tbl = nd_table(dev_net(dev)); 404 405 return __neigh_create(tbl, pkey, dev, false); 406 } 407 408 static inline void __ipv6_confirm_neigh(struct net_device *dev, 409 const void *pkey) 410 { 411 struct neighbour *n; 412 413 rcu_read_lock(); 414 n = __ipv6_neigh_lookup_noref(dev, pkey); 415 neigh_confirm(n); 416 rcu_read_unlock(); 417 } 418 419 static inline struct neighbour *ip_neigh_gw6(struct net_device *dev, 420 const void *addr) 421 { 422 #if IS_ENABLED(CONFIG_IPV6) 423 struct neighbour *neigh; 424 425 neigh = __ipv6_neigh_lookup_noref(dev, addr); 426 if (unlikely(!neigh)) 427 neigh = ipv6_neigh_create_noref(dev, addr); 428 429 return neigh; 430 #else 431 return ERR_PTR(-EAFNOSUPPORT); 432 #endif 433 } 434 435 int ndisc_init(void); 436 int ndisc_late_init(void); 437 438 void ndisc_late_cleanup(void); 439 void ndisc_cleanup(void); 440 441 enum skb_drop_reason ndisc_rcv(struct sk_buff *skb); 442 443 struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit, 444 const struct in6_addr *saddr, u64 nonce); 445 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, 446 const struct in6_addr *daddr, const struct in6_addr *saddr, 447 u64 nonce); 448 449 void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr, 450 const struct in6_addr *saddr); 451 452 void ndisc_send_rs(struct net_device *dev, 453 const struct in6_addr *saddr, const struct in6_addr *daddr); 454 455 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr, 456 const struct in6_addr *solicited_addr, 457 bool router, bool solicited, bool override, bool inc_opt); 458 459 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target); 460 461 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, 462 int dir); 463 464 void ndisc_update(const struct net_device *dev, struct neighbour *neigh, 465 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type, 466 struct ndisc_options *ndopts); 467 468 int ndisc_check_ns_na(struct sk_buff *skb); 469 470 /* 471 * IGMP 472 */ 473 int igmp6_init(void); 474 int igmp6_late_init(void); 475 476 void igmp6_cleanup(void); 477 void igmp6_late_cleanup(void); 478 479 void igmp6_event_query(struct sk_buff *skb); 480 481 void igmp6_event_report(struct sk_buff *skb); 482 483 484 #ifdef CONFIG_SYSCTL 485 int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write, 486 void *buffer, size_t *lenp, loff_t *ppos); 487 #endif 488 489 void inet6_ifinfo_notify(int event, struct inet6_dev *idev); 490 491 #endif 492