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