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_MAX 42 }; 43 44 #define MAX_RTR_SOLICITATION_DELAY HZ 45 46 #define ND_REACHABLE_TIME (30*HZ) 47 #define ND_RETRANS_TIMER HZ 48 49 #include <linux/compiler.h> 50 #include <linux/icmpv6.h> 51 #include <linux/in6.h> 52 #include <linux/types.h> 53 #include <linux/if_arp.h> 54 #include <linux/netdevice.h> 55 #include <linux/hash.h> 56 57 #include <net/neighbour.h> 58 59 /* Set to 3 to get tracing... */ 60 #define ND_DEBUG 1 61 62 #define ND_PRINTK(val, level, fmt, ...) \ 63 do { \ 64 if (val <= ND_DEBUG) \ 65 net_##level##_ratelimited(fmt, ##__VA_ARGS__); \ 66 } while (0) 67 68 struct ctl_table; 69 struct inet6_dev; 70 struct net_device; 71 struct net_proto_family; 72 struct sk_buff; 73 struct prefix_info; 74 75 extern struct neigh_table nd_tbl; 76 77 struct nd_msg { 78 struct icmp6hdr icmph; 79 struct in6_addr target; 80 __u8 opt[0]; 81 }; 82 83 struct rs_msg { 84 struct icmp6hdr icmph; 85 __u8 opt[0]; 86 }; 87 88 struct ra_msg { 89 struct icmp6hdr icmph; 90 __be32 reachable_time; 91 __be32 retrans_timer; 92 }; 93 94 struct rd_msg { 95 struct icmp6hdr icmph; 96 struct in6_addr target; 97 struct in6_addr dest; 98 __u8 opt[0]; 99 }; 100 101 struct nd_opt_hdr { 102 __u8 nd_opt_type; 103 __u8 nd_opt_len; 104 } __packed; 105 106 /* ND options */ 107 struct ndisc_options { 108 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX]; 109 #ifdef CONFIG_IPV6_ROUTE_INFO 110 struct nd_opt_hdr *nd_opts_ri; 111 struct nd_opt_hdr *nd_opts_ri_end; 112 #endif 113 struct nd_opt_hdr *nd_useropts; 114 struct nd_opt_hdr *nd_useropts_end; 115 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 116 struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1]; 117 #endif 118 }; 119 120 #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR] 121 #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR] 122 #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO] 123 #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END] 124 #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR] 125 #define nd_opts_mtu nd_opt_array[ND_OPT_MTU] 126 #define nd_opts_nonce nd_opt_array[ND_OPT_NONCE] 127 #define nd_802154_opts_src_lladdr nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR] 128 #define nd_802154_opts_tgt_lladdr nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR] 129 130 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7) 131 132 struct ndisc_options *ndisc_parse_options(const struct net_device *dev, 133 u8 *opt, int opt_len, 134 struct ndisc_options *ndopts); 135 136 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data, 137 int data_len, int pad); 138 139 #define NDISC_OPS_REDIRECT_DATA_SPACE 2 140 141 /* 142 * This structure defines the hooks for IPv6 neighbour discovery. 143 * The following hooks can be defined; unless noted otherwise, they are 144 * optional and can be filled with a null pointer. 145 * 146 * int (*is_useropt)(u8 nd_opt_type): 147 * This function is called when IPv6 decide RA userspace options. if 148 * this function returns 1 then the option given by nd_opt_type will 149 * be handled as userspace option additional to the IPv6 options. 150 * 151 * int (*parse_options)(const struct net_device *dev, 152 * struct nd_opt_hdr *nd_opt, 153 * struct ndisc_options *ndopts): 154 * This function is called while parsing ndisc ops and put each position 155 * as pointer into ndopts. If this function return unequal 0, then this 156 * function took care about the ndisc option, if 0 then the IPv6 ndisc 157 * option parser will take care about that option. 158 * 159 * void (*update)(const struct net_device *dev, struct neighbour *n, 160 * u32 flags, u8 icmp6_type, 161 * const struct ndisc_options *ndopts): 162 * This function is called when IPv6 ndisc updates the neighbour cache 163 * entry. Additional options which can be updated may be previously 164 * parsed by parse_opts callback and accessible over ndopts parameter. 165 * 166 * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type, 167 * struct neighbour *neigh, u8 *ha_buf, 168 * u8 **ha): 169 * This function is called when the necessary option space will be 170 * calculated before allocating a skb. The parameters neigh, ha_buf 171 * abd ha are available on NDISC_REDIRECT messages only. 172 * 173 * void (*fill_addr_option)(const struct net_device *dev, 174 * struct sk_buff *skb, u8 icmp6_type, 175 * const u8 *ha): 176 * This function is called when the skb will finally fill the option 177 * fields inside skb. NOTE: this callback should fill the option 178 * fields to the skb which are previously indicated by opt_space 179 * parameter. That means the decision to add such option should 180 * not lost between these two callbacks, e.g. protected by interface 181 * up state. 182 * 183 * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev, 184 * const struct prefix_info *pinfo, 185 * struct inet6_dev *in6_dev, 186 * struct in6_addr *addr, 187 * int addr_type, u32 addr_flags, 188 * bool sllao, bool tokenized, 189 * __u32 valid_lft, u32 prefered_lft, 190 * bool dev_addr_generated): 191 * This function is called when a RA messages is received with valid 192 * PIO option fields and an IPv6 address will be added to the interface 193 * for autoconfiguration. The parameter dev_addr_generated reports about 194 * if the address was based on dev->dev_addr or not. This can be used 195 * to add a second address if link-layer operates with two link layer 196 * addresses. E.g. 802.15.4 6LoWPAN. 197 */ 198 struct ndisc_ops { 199 int (*is_useropt)(u8 nd_opt_type); 200 int (*parse_options)(const struct net_device *dev, 201 struct nd_opt_hdr *nd_opt, 202 struct ndisc_options *ndopts); 203 void (*update)(const struct net_device *dev, struct neighbour *n, 204 u32 flags, u8 icmp6_type, 205 const struct ndisc_options *ndopts); 206 int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type, 207 struct neighbour *neigh, u8 *ha_buf, 208 u8 **ha); 209 void (*fill_addr_option)(const struct net_device *dev, 210 struct sk_buff *skb, u8 icmp6_type, 211 const u8 *ha); 212 void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev, 213 const struct prefix_info *pinfo, 214 struct inet6_dev *in6_dev, 215 struct in6_addr *addr, 216 int addr_type, u32 addr_flags, 217 bool sllao, bool tokenized, 218 __u32 valid_lft, u32 prefered_lft, 219 bool dev_addr_generated); 220 }; 221 222 #if IS_ENABLED(CONFIG_IPV6) 223 static inline int ndisc_ops_is_useropt(const struct net_device *dev, 224 u8 nd_opt_type) 225 { 226 if (dev->ndisc_ops && dev->ndisc_ops->is_useropt) 227 return dev->ndisc_ops->is_useropt(nd_opt_type); 228 else 229 return 0; 230 } 231 232 static inline int ndisc_ops_parse_options(const struct net_device *dev, 233 struct nd_opt_hdr *nd_opt, 234 struct ndisc_options *ndopts) 235 { 236 if (dev->ndisc_ops && dev->ndisc_ops->parse_options) 237 return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts); 238 else 239 return 0; 240 } 241 242 static inline void ndisc_ops_update(const struct net_device *dev, 243 struct neighbour *n, u32 flags, 244 u8 icmp6_type, 245 const struct ndisc_options *ndopts) 246 { 247 if (dev->ndisc_ops && dev->ndisc_ops->update) 248 dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts); 249 } 250 251 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev, 252 u8 icmp6_type) 253 { 254 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space && 255 icmp6_type != NDISC_REDIRECT) 256 return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL, 257 NULL, NULL); 258 else 259 return 0; 260 } 261 262 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev, 263 struct neighbour *neigh, 264 u8 *ha_buf, u8 **ha) 265 { 266 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space) 267 return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT, 268 neigh, ha_buf, ha); 269 else 270 return 0; 271 } 272 273 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev, 274 struct sk_buff *skb, 275 u8 icmp6_type) 276 { 277 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option && 278 icmp6_type != NDISC_REDIRECT) 279 dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL); 280 } 281 282 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev, 283 struct sk_buff *skb, 284 const u8 *ha) 285 { 286 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option) 287 dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha); 288 } 289 290 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net, 291 struct net_device *dev, 292 const struct prefix_info *pinfo, 293 struct inet6_dev *in6_dev, 294 struct in6_addr *addr, 295 int addr_type, u32 addr_flags, 296 bool sllao, bool tokenized, 297 __u32 valid_lft, 298 u32 prefered_lft, 299 bool dev_addr_generated) 300 { 301 if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr) 302 dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev, 303 addr, addr_type, 304 addr_flags, sllao, 305 tokenized, valid_lft, 306 prefered_lft, 307 dev_addr_generated); 308 } 309 #endif 310 311 /* 312 * Return the padding between the option length and the start of the 313 * link addr. Currently only IP-over-InfiniBand needs this, although 314 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may 315 * also need a pad of 2. 316 */ 317 static inline int ndisc_addr_option_pad(unsigned short type) 318 { 319 switch (type) { 320 case ARPHRD_INFINIBAND: return 2; 321 default: return 0; 322 } 323 } 324 325 static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad) 326 { 327 return NDISC_OPT_SPACE(addr_len + pad); 328 } 329 330 #if IS_ENABLED(CONFIG_IPV6) 331 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type) 332 { 333 return __ndisc_opt_addr_space(dev->addr_len, 334 ndisc_addr_option_pad(dev->type)) + 335 ndisc_ops_opt_addr_space(dev, icmp6_type); 336 } 337 338 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev, 339 struct neighbour *neigh, 340 u8 *ops_data_buf, 341 u8 **ops_data) 342 { 343 return __ndisc_opt_addr_space(dev->addr_len, 344 ndisc_addr_option_pad(dev->type)) + 345 ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf, 346 ops_data); 347 } 348 #endif 349 350 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p, 351 unsigned char addr_len, int prepad) 352 { 353 u8 *lladdr = (u8 *)(p + 1); 354 int lladdrlen = p->nd_opt_len << 3; 355 if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad)) 356 return NULL; 357 return lladdr + prepad; 358 } 359 360 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p, 361 struct net_device *dev) 362 { 363 return __ndisc_opt_addr_data(p, dev->addr_len, 364 ndisc_addr_option_pad(dev->type)); 365 } 366 367 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd) 368 { 369 const u32 *p32 = pkey; 370 371 return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) + 372 (p32[1] * hash_rnd[1]) + 373 (p32[2] * hash_rnd[2]) + 374 (p32[3] * hash_rnd[3])); 375 } 376 377 static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey) 378 { 379 return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev); 380 } 381 382 static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey) 383 { 384 struct neighbour *n; 385 386 rcu_read_lock_bh(); 387 n = __ipv6_neigh_lookup_noref(dev, pkey); 388 if (n && !refcount_inc_not_zero(&n->refcnt)) 389 n = NULL; 390 rcu_read_unlock_bh(); 391 392 return n; 393 } 394 395 static inline void __ipv6_confirm_neigh(struct net_device *dev, 396 const void *pkey) 397 { 398 struct neighbour *n; 399 400 rcu_read_lock_bh(); 401 n = __ipv6_neigh_lookup_noref(dev, pkey); 402 if (n) { 403 unsigned long now = jiffies; 404 405 /* avoid dirtying neighbour */ 406 if (n->confirmed != now) 407 n->confirmed = now; 408 } 409 rcu_read_unlock_bh(); 410 } 411 412 int ndisc_init(void); 413 int ndisc_late_init(void); 414 415 void ndisc_late_cleanup(void); 416 void ndisc_cleanup(void); 417 418 int ndisc_rcv(struct sk_buff *skb); 419 420 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, 421 const struct in6_addr *daddr, const struct in6_addr *saddr, 422 u64 nonce); 423 424 void ndisc_send_rs(struct net_device *dev, 425 const struct in6_addr *saddr, const struct in6_addr *daddr); 426 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr, 427 const struct in6_addr *solicited_addr, 428 bool router, bool solicited, bool override, bool inc_opt); 429 430 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target); 431 432 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, 433 int dir); 434 435 void ndisc_update(const struct net_device *dev, struct neighbour *neigh, 436 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type, 437 struct ndisc_options *ndopts); 438 439 /* 440 * IGMP 441 */ 442 int igmp6_init(void); 443 int igmp6_late_init(void); 444 445 void igmp6_cleanup(void); 446 void igmp6_late_cleanup(void); 447 448 int igmp6_event_query(struct sk_buff *skb); 449 450 int igmp6_event_report(struct sk_buff *skb); 451 452 453 #ifdef CONFIG_SYSCTL 454 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, 455 void __user *buffer, size_t *lenp, loff_t *ppos); 456 int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl, 457 void __user *oldval, size_t __user *oldlenp, 458 void __user *newval, size_t newlen); 459 #endif 460 461 void inet6_ifinfo_notify(int event, struct inet6_dev *idev); 462 463 #endif 464