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 (*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();
399 n = __ipv6_neigh_lookup_noref(dev, pkey);
400 if (n && !refcount_inc_not_zero(&n->refcnt))
401 n = NULL;
402 rcu_read_unlock();
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();
413 n = __ipv6_neigh_lookup_noref(dev, pkey);
414 neigh_confirm(n);
415 rcu_read_unlock();
416 }
417
418 static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
419 const void *pkey)
420 {
421 struct neighbour *n;
422
423 rcu_read_lock();
424 n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
425 neigh_confirm(n);
426 rcu_read_unlock();
427 }
428
429 /* uses ipv6_stub and is meant for use outside of IPv6 core */
430 static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
431 const void *addr)
432 {
433 struct neighbour *neigh;
434
435 neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
436 if (unlikely(!neigh))
437 neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
438
439 return neigh;
440 }
441
442 int ndisc_init(void);
443 int ndisc_late_init(void);
444
445 void ndisc_late_cleanup(void);
446 void ndisc_cleanup(void);
447
448 enum skb_drop_reason ndisc_rcv(struct sk_buff *skb);
449
450 struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
451 const struct in6_addr *saddr, u64 nonce);
452 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
453 const struct in6_addr *daddr, const struct in6_addr *saddr,
454 u64 nonce);
455
456 void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
457 const struct in6_addr *saddr);
458
459 void ndisc_send_rs(struct net_device *dev,
460 const struct in6_addr *saddr, const struct in6_addr *daddr);
461 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
462 const struct in6_addr *solicited_addr,
463 bool router, bool solicited, bool override, bool inc_opt);
464
465 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
466
467 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
468 int dir);
469
470 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
471 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
472 struct ndisc_options *ndopts);
473
474 /*
475 * IGMP
476 */
477 int igmp6_init(void);
478 int igmp6_late_init(void);
479
480 void igmp6_cleanup(void);
481 void igmp6_late_cleanup(void);
482
483 void igmp6_event_query(struct sk_buff *skb);
484
485 void igmp6_event_report(struct sk_buff *skb);
486
487
488 #ifdef CONFIG_SYSCTL
489 int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write,
490 void *buffer, size_t *lenp, loff_t *ppos);
491 #endif
492
493 void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
494
495 #endif
496
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