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)
ndisc_ops_is_useropt(const struct net_device * dev,u8 nd_opt_type)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
ndisc_ops_parse_options(const struct net_device * dev,struct nd_opt_hdr * nd_opt,struct ndisc_options * ndopts)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
ndisc_ops_update(const struct net_device * dev,struct neighbour * n,u32 flags,u8 icmp6_type,const struct ndisc_options * ndopts)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
ndisc_ops_opt_addr_space(const struct net_device * dev,u8 icmp6_type)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
ndisc_ops_redirect_opt_addr_space(const struct net_device * dev,struct neighbour * neigh,u8 * ha_buf,u8 ** ha)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
ndisc_ops_fill_addr_option(const struct net_device * dev,struct sk_buff * skb,u8 icmp6_type)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
ndisc_ops_fill_redirect_addr_option(const struct net_device * dev,struct sk_buff * skb,const u8 * ha)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
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)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 */
ndisc_addr_option_pad(unsigned short type)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
__ndisc_opt_addr_space(unsigned char addr_len,int pad)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)
ndisc_opt_addr_space(struct net_device * dev,u8 icmp6_type)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
ndisc_redirect_opt_addr_space(struct net_device * dev,struct neighbour * neigh,u8 * ops_data_buf,u8 ** ops_data)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
__ndisc_opt_addr_data(struct nd_opt_hdr * p,unsigned char addr_len,int prepad)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
ndisc_opt_addr_data(struct nd_opt_hdr * p,struct net_device * dev)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
ndisc_hashfn(const void * pkey,const struct net_device * dev,__u32 * hash_rnd)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
__ipv6_neigh_lookup_noref(struct net_device * dev,const void * pkey)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
__ipv6_neigh_lookup(struct net_device * dev,const void * pkey)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
__ipv6_confirm_neigh(struct net_device * dev,const void * pkey)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