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, 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 */ 202 struct 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) 227 static 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 } 235 236 static 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 } 245 246 static 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 } 254 255 static 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 } 265 266 static 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 } 276 277 static 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 } 285 286 static 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 } 293 294 static 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 */ 321 static 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 } 328 329 static 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) 335 static 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 } 341 342 static 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 353 354 static 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 } 363 364 static 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 } 370 371 static 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 } 380 381 static 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 } 385 386 static inline 387 struct 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 } 393 394 static 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 } 406 407 static 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 } 423 424 static 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 */ 442 static 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 } 453 454 int ndisc_init(void); 455 int ndisc_late_init(void); 456 457 void ndisc_late_cleanup(void); 458 void ndisc_cleanup(void); 459 460 int ndisc_rcv(struct sk_buff *skb); 461 462 void 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); 465 466 void ndisc_send_rs(struct net_device *dev, 467 const struct in6_addr *saddr, const struct in6_addr *daddr); 468 void 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); 471 472 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target); 473 474 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, 475 int dir); 476 477 void 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 */ 484 int igmp6_init(void); 485 int igmp6_late_init(void); 486 487 void igmp6_cleanup(void); 488 void igmp6_late_cleanup(void); 489 490 int igmp6_event_query(struct sk_buff *skb); 491 492 int igmp6_event_report(struct sk_buff *skb); 493 494 495 #ifdef CONFIG_SYSCTL 496 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, 497 void *buffer, size_t *lenp, loff_t *ppos); 498 int 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 502 503 void inet6_ifinfo_notify(int event, struct inet6_dev *idev); 504 505 #endif 506