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