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 (*parse_options)(const struct net_device *dev,
151 * struct nd_opt_hdr *nd_opt,
152 * struct ndisc_options *ndopts):
153 * This function is called while parsing ndisc ops and put each position
154 * as pointer into ndopts. If this function return unequal 0, then this
155 * function took care about the ndisc option, if 0 then the IPv6 ndisc
156 * option parser will take care about that option.
157 *
158 * void (*update)(const struct net_device *dev, struct neighbour *n,
159 * u32 flags, u8 icmp6_type,
160 * const struct ndisc_options *ndopts):
161 * This function is called when IPv6 ndisc updates the neighbour cache
162 * entry. Additional options which can be updated may be previously
163 * parsed by parse_opts callback and accessible over ndopts parameter.
164 *
165 * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
166 * struct neighbour *neigh, u8 *ha_buf,
167 * u8 **ha):
168 * This function is called when the necessary option space will be
169 * calculated before allocating a skb. The parameters neigh, ha_buf
170 * abd ha are available on NDISC_REDIRECT messages only.
171 *
172 * void (*fill_addr_option)(const struct net_device *dev,
173 * struct sk_buff *skb, u8 icmp6_type,
174 * const u8 *ha):
175 * This function is called when the skb will finally fill the option
176 * fields inside skb. NOTE: this callback should fill the option
177 * fields to the skb which are previously indicated by opt_space
178 * parameter. That means the decision to add such option should
179 * not lost between these two callbacks, e.g. protected by interface
180 * up state.
181 *
182 * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
183 * const struct prefix_info *pinfo,
184 * struct inet6_dev *in6_dev,
185 * struct in6_addr *addr,
186 * int addr_type, u32 addr_flags,
187 * bool sllao, bool tokenized,
188 * __u32 valid_lft, u32 prefered_lft,
189 * bool dev_addr_generated):
190 * This function is called when a RA messages is received with valid
191 * PIO option fields and an IPv6 address will be added to the interface
192 * for autoconfiguration. The parameter dev_addr_generated reports about
193 * if the address was based on dev->dev_addr or not. This can be used
194 * to add a second address if link-layer operates with two link layer
195 * addresses. E.g. 802.15.4 6LoWPAN.
196 */
197 struct ndisc_ops {
198 int (*parse_options)(const struct net_device *dev,
199 struct nd_opt_hdr *nd_opt,
200 struct ndisc_options *ndopts);
201 void (*update)(const struct net_device *dev, struct neighbour *n,
202 u32 flags, u8 icmp6_type,
203 const struct ndisc_options *ndopts);
204 int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
205 struct neighbour *neigh, u8 *ha_buf,
206 u8 **ha);
207 void (*fill_addr_option)(const struct net_device *dev,
208 struct sk_buff *skb, u8 icmp6_type,
209 const u8 *ha);
210 void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
211 const struct prefix_info *pinfo,
212 struct inet6_dev *in6_dev,
213 struct in6_addr *addr,
214 int addr_type, u32 addr_flags,
215 bool sllao, bool tokenized,
216 __u32 valid_lft, u32 prefered_lft,
217 bool dev_addr_generated);
218 };
219
220 #if IS_ENABLED(CONFIG_IPV6)
ndisc_ops_parse_options(const struct net_device * dev,struct nd_opt_hdr * nd_opt,struct ndisc_options * ndopts)221 static inline int ndisc_ops_parse_options(const struct net_device *dev,
222 struct nd_opt_hdr *nd_opt,
223 struct ndisc_options *ndopts)
224 {
225 if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
226 return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
227 else
228 return 0;
229 }
230
ndisc_ops_update(const struct net_device * dev,struct neighbour * n,u32 flags,u8 icmp6_type,const struct ndisc_options * ndopts)231 static inline void ndisc_ops_update(const struct net_device *dev,
232 struct neighbour *n, u32 flags,
233 u8 icmp6_type,
234 const struct ndisc_options *ndopts)
235 {
236 if (dev->ndisc_ops && dev->ndisc_ops->update)
237 dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
238 }
239
ndisc_ops_opt_addr_space(const struct net_device * dev,u8 icmp6_type)240 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
241 u8 icmp6_type)
242 {
243 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
244 icmp6_type != NDISC_REDIRECT)
245 return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
246 NULL, NULL);
247 else
248 return 0;
249 }
250
ndisc_ops_redirect_opt_addr_space(const struct net_device * dev,struct neighbour * neigh,u8 * ha_buf,u8 ** ha)251 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
252 struct neighbour *neigh,
253 u8 *ha_buf, u8 **ha)
254 {
255 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
256 return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
257 neigh, ha_buf, ha);
258 else
259 return 0;
260 }
261
ndisc_ops_fill_addr_option(const struct net_device * dev,struct sk_buff * skb,u8 icmp6_type)262 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
263 struct sk_buff *skb,
264 u8 icmp6_type)
265 {
266 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
267 icmp6_type != NDISC_REDIRECT)
268 dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
269 }
270
ndisc_ops_fill_redirect_addr_option(const struct net_device * dev,struct sk_buff * skb,const u8 * ha)271 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
272 struct sk_buff *skb,
273 const u8 *ha)
274 {
275 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
276 dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
277 }
278
ndisc_ops_prefix_rcv_add_addr(struct net * net,struct net_device * dev,const struct prefix_info * pinfo,struct inet6_dev * in6_dev,struct in6_addr * addr,int addr_type,u32 addr_flags,bool sllao,bool tokenized,__u32 valid_lft,u32 prefered_lft,bool dev_addr_generated)279 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
280 struct net_device *dev,
281 const struct prefix_info *pinfo,
282 struct inet6_dev *in6_dev,
283 struct in6_addr *addr,
284 int addr_type, u32 addr_flags,
285 bool sllao, bool tokenized,
286 __u32 valid_lft,
287 u32 prefered_lft,
288 bool dev_addr_generated)
289 {
290 if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
291 dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
292 addr, addr_type,
293 addr_flags, sllao,
294 tokenized, valid_lft,
295 prefered_lft,
296 dev_addr_generated);
297 }
298 #endif
299
300 /*
301 * Return the padding between the option length and the start of the
302 * link addr. Currently only IP-over-InfiniBand needs this, although
303 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
304 * also need a pad of 2.
305 */
ndisc_addr_option_pad(unsigned short type)306 static inline int ndisc_addr_option_pad(unsigned short type)
307 {
308 switch (type) {
309 case ARPHRD_INFINIBAND: return 2;
310 default: return 0;
311 }
312 }
313
__ndisc_opt_addr_space(unsigned char addr_len,int pad)314 static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
315 {
316 return NDISC_OPT_SPACE(addr_len + pad);
317 }
318
319 #if IS_ENABLED(CONFIG_IPV6)
ndisc_opt_addr_space(struct net_device * dev,u8 icmp6_type)320 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
321 {
322 return __ndisc_opt_addr_space(dev->addr_len,
323 ndisc_addr_option_pad(dev->type)) +
324 ndisc_ops_opt_addr_space(dev, icmp6_type);
325 }
326
ndisc_redirect_opt_addr_space(struct net_device * dev,struct neighbour * neigh,u8 * ops_data_buf,u8 ** ops_data)327 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
328 struct neighbour *neigh,
329 u8 *ops_data_buf,
330 u8 **ops_data)
331 {
332 return __ndisc_opt_addr_space(dev->addr_len,
333 ndisc_addr_option_pad(dev->type)) +
334 ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
335 ops_data);
336 }
337 #endif
338
__ndisc_opt_addr_data(struct nd_opt_hdr * p,unsigned char addr_len,int prepad)339 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
340 unsigned char addr_len, int prepad)
341 {
342 u8 *lladdr = (u8 *)(p + 1);
343 int lladdrlen = p->nd_opt_len << 3;
344 if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
345 return NULL;
346 return lladdr + prepad;
347 }
348
ndisc_opt_addr_data(struct nd_opt_hdr * p,struct net_device * dev)349 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
350 struct net_device *dev)
351 {
352 return __ndisc_opt_addr_data(p, dev->addr_len,
353 ndisc_addr_option_pad(dev->type));
354 }
355
ndisc_hashfn(const void * pkey,const struct net_device * dev,__u32 * hash_rnd)356 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
357 {
358 const u32 *p32 = pkey;
359
360 return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
361 (p32[1] * hash_rnd[1]) +
362 (p32[2] * hash_rnd[2]) +
363 (p32[3] * hash_rnd[3]));
364 }
365
__ipv6_neigh_lookup_noref(struct net_device * dev,const void * pkey)366 static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
367 {
368 return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
369 }
370
371 static inline
__ipv6_neigh_lookup_noref_stub(struct net_device * dev,const void * pkey)372 struct neighbour *__ipv6_neigh_lookup_noref_stub(struct net_device *dev,
373 const void *pkey)
374 {
375 return ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128,
376 ndisc_hashfn, pkey, dev);
377 }
378
__ipv6_neigh_lookup(struct net_device * dev,const void * pkey)379 static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
380 {
381 struct neighbour *n;
382
383 rcu_read_lock();
384 n = __ipv6_neigh_lookup_noref(dev, pkey);
385 if (n && !refcount_inc_not_zero(&n->refcnt))
386 n = NULL;
387 rcu_read_unlock();
388
389 return n;
390 }
391
__ipv6_confirm_neigh(struct net_device * dev,const void * pkey)392 static inline void __ipv6_confirm_neigh(struct net_device *dev,
393 const void *pkey)
394 {
395 struct neighbour *n;
396
397 rcu_read_lock();
398 n = __ipv6_neigh_lookup_noref(dev, pkey);
399 neigh_confirm(n);
400 rcu_read_unlock();
401 }
402
__ipv6_confirm_neigh_stub(struct net_device * dev,const void * pkey)403 static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
404 const void *pkey)
405 {
406 struct neighbour *n;
407
408 rcu_read_lock();
409 n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
410 neigh_confirm(n);
411 rcu_read_unlock();
412 }
413
414 /* uses ipv6_stub and is meant for use outside of IPv6 core */
ip_neigh_gw6(struct net_device * dev,const void * addr)415 static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
416 const void *addr)
417 {
418 struct neighbour *neigh;
419
420 neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
421 if (unlikely(!neigh))
422 neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
423
424 return neigh;
425 }
426
427 int ndisc_init(void);
428 int ndisc_late_init(void);
429
430 void ndisc_late_cleanup(void);
431 void ndisc_cleanup(void);
432
433 enum skb_drop_reason ndisc_rcv(struct sk_buff *skb);
434
435 struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
436 const struct in6_addr *saddr, u64 nonce);
437 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
438 const struct in6_addr *daddr, const struct in6_addr *saddr,
439 u64 nonce);
440
441 void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
442 const struct in6_addr *saddr);
443
444 void ndisc_send_rs(struct net_device *dev,
445 const struct in6_addr *saddr, const struct in6_addr *daddr);
446 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
447 const struct in6_addr *solicited_addr,
448 bool router, bool solicited, bool override, bool inc_opt);
449
450 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
451
452 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
453 int dir);
454
455 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
456 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
457 struct ndisc_options *ndopts);
458
459 /*
460 * IGMP
461 */
462 int igmp6_init(void);
463 int igmp6_late_init(void);
464
465 void igmp6_cleanup(void);
466 void igmp6_late_cleanup(void);
467
468 void igmp6_event_query(struct sk_buff *skb);
469
470 void igmp6_event_report(struct sk_buff *skb);
471
472
473 #ifdef CONFIG_SYSCTL
474 int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write,
475 void *buffer, size_t *lenp, loff_t *ppos);
476 #endif
477
478 void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
479
480 #endif
481