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