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, /* RFC-ietf-6man-ra-pref64-09 */
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 /* Set to 3 to get tracing... */
62 #define ND_DEBUG 1
63
64 #define ND_PRINTK(val, level, fmt, ...) \
65 do { \
66 if (val <= ND_DEBUG) \
67 net_##level##_ratelimited(fmt, ##__VA_ARGS__); \
68 } while (0)
69
70 struct ctl_table;
71 struct inet6_dev;
72 struct net_device;
73 struct net_proto_family;
74 struct sk_buff;
75 struct prefix_info;
76
77 extern struct neigh_table nd_tbl;
78
79 struct nd_msg {
80 struct icmp6hdr icmph;
81 struct in6_addr target;
82 __u8 opt[0];
83 };
84
85 struct rs_msg {
86 struct icmp6hdr icmph;
87 __u8 opt[0];
88 };
89
90 struct ra_msg {
91 struct icmp6hdr icmph;
92 __be32 reachable_time;
93 __be32 retrans_timer;
94 };
95
96 struct rd_msg {
97 struct icmp6hdr icmph;
98 struct in6_addr target;
99 struct in6_addr dest;
100 __u8 opt[0];
101 };
102
103 struct nd_opt_hdr {
104 __u8 nd_opt_type;
105 __u8 nd_opt_len;
106 } __packed;
107
108 /* ND options */
109 struct ndisc_options {
110 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
111 #ifdef CONFIG_IPV6_ROUTE_INFO
112 struct nd_opt_hdr *nd_opts_ri;
113 struct nd_opt_hdr *nd_opts_ri_end;
114 #endif
115 struct nd_opt_hdr *nd_useropts;
116 struct nd_opt_hdr *nd_useropts_end;
117 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
118 struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
119 #endif
120 };
121
122 #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
123 #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR]
124 #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO]
125 #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END]
126 #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR]
127 #define nd_opts_mtu nd_opt_array[ND_OPT_MTU]
128 #define nd_opts_nonce nd_opt_array[ND_OPT_NONCE]
129 #define nd_802154_opts_src_lladdr nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
130 #define nd_802154_opts_tgt_lladdr nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
131
132 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
133
134 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
135 u8 *opt, int opt_len,
136 struct ndisc_options *ndopts);
137
138 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
139 int data_len, int pad);
140
141 #define NDISC_OPS_REDIRECT_DATA_SPACE 2
142
143 /*
144 * This structure defines the hooks for IPv6 neighbour discovery.
145 * The following hooks can be defined; unless noted otherwise, they are
146 * optional and can be filled with a null pointer.
147 *
148 * int (*is_useropt)(u8 nd_opt_type):
149 * This function is called when IPv6 decide RA userspace options. if
150 * this function returns 1 then the option given by nd_opt_type will
151 * be handled as userspace option additional to the IPv6 options.
152 *
153 * int (*parse_options)(const struct net_device *dev,
154 * struct nd_opt_hdr *nd_opt,
155 * struct ndisc_options *ndopts):
156 * This function is called while parsing ndisc ops and put each position
157 * as pointer into ndopts. If this function return unequal 0, then this
158 * function took care about the ndisc option, if 0 then the IPv6 ndisc
159 * option parser will take care about that option.
160 *
161 * void (*update)(const struct net_device *dev, struct neighbour *n,
162 * u32 flags, u8 icmp6_type,
163 * const struct ndisc_options *ndopts):
164 * This function is called when IPv6 ndisc updates the neighbour cache
165 * entry. Additional options which can be updated may be previously
166 * parsed by parse_opts callback and accessible over ndopts parameter.
167 *
168 * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
169 * struct neighbour *neigh, u8 *ha_buf,
170 * u8 **ha):
171 * This function is called when the necessary option space will be
172 * calculated before allocating a skb. The parameters neigh, ha_buf
173 * abd ha are available on NDISC_REDIRECT messages only.
174 *
175 * void (*fill_addr_option)(const struct net_device *dev,
176 * struct sk_buff *skb, u8 icmp6_type,
177 * const u8 *ha):
178 * This function is called when the skb will finally fill the option
179 * fields inside skb. NOTE: this callback should fill the option
180 * fields to the skb which are previously indicated by opt_space
181 * parameter. That means the decision to add such option should
182 * not lost between these two callbacks, e.g. protected by interface
183 * up state.
184 *
185 * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
186 * const struct prefix_info *pinfo,
187 * struct inet6_dev *in6_dev,
188 * struct in6_addr *addr,
189 * int addr_type, u32 addr_flags,
190 * bool sllao, bool tokenized,
191 * __u32 valid_lft, u32 prefered_lft,
192 * bool dev_addr_generated):
193 * This function is called when a RA messages is received with valid
194 * PIO option fields and an IPv6 address will be added to the interface
195 * for autoconfiguration. The parameter dev_addr_generated reports about
196 * if the address was based on dev->dev_addr or not. This can be used
197 * to add a second address if link-layer operates with two link layer
198 * addresses. E.g. 802.15.4 6LoWPAN.
199 */
200 struct ndisc_ops {
201 int (*is_useropt)(u8 nd_opt_type);
202 int (*parse_options)(const struct net_device *dev,
203 struct nd_opt_hdr *nd_opt,
204 struct ndisc_options *ndopts);
205 void (*update)(const struct net_device *dev, struct neighbour *n,
206 u32 flags, u8 icmp6_type,
207 const struct ndisc_options *ndopts);
208 int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
209 struct neighbour *neigh, u8 *ha_buf,
210 u8 **ha);
211 void (*fill_addr_option)(const struct net_device *dev,
212 struct sk_buff *skb, u8 icmp6_type,
213 const u8 *ha);
214 void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
215 const struct prefix_info *pinfo,
216 struct inet6_dev *in6_dev,
217 struct in6_addr *addr,
218 int addr_type, u32 addr_flags,
219 bool sllao, bool tokenized,
220 __u32 valid_lft, u32 prefered_lft,
221 bool dev_addr_generated);
222 };
223
224 #if IS_ENABLED(CONFIG_IPV6)
ndisc_ops_is_useropt(const struct net_device * dev,u8 nd_opt_type)225 static inline int ndisc_ops_is_useropt(const struct net_device *dev,
226 u8 nd_opt_type)
227 {
228 if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
229 return dev->ndisc_ops->is_useropt(nd_opt_type);
230 else
231 return 0;
232 }
233
ndisc_ops_parse_options(const struct net_device * dev,struct nd_opt_hdr * nd_opt,struct ndisc_options * ndopts)234 static inline int ndisc_ops_parse_options(const struct net_device *dev,
235 struct nd_opt_hdr *nd_opt,
236 struct ndisc_options *ndopts)
237 {
238 if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
239 return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
240 else
241 return 0;
242 }
243
ndisc_ops_update(const struct net_device * dev,struct neighbour * n,u32 flags,u8 icmp6_type,const struct ndisc_options * ndopts)244 static inline void ndisc_ops_update(const struct net_device *dev,
245 struct neighbour *n, u32 flags,
246 u8 icmp6_type,
247 const struct ndisc_options *ndopts)
248 {
249 if (dev->ndisc_ops && dev->ndisc_ops->update)
250 dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
251 }
252
ndisc_ops_opt_addr_space(const struct net_device * dev,u8 icmp6_type)253 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
254 u8 icmp6_type)
255 {
256 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
257 icmp6_type != NDISC_REDIRECT)
258 return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
259 NULL, NULL);
260 else
261 return 0;
262 }
263
ndisc_ops_redirect_opt_addr_space(const struct net_device * dev,struct neighbour * neigh,u8 * ha_buf,u8 ** ha)264 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
265 struct neighbour *neigh,
266 u8 *ha_buf, u8 **ha)
267 {
268 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
269 return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
270 neigh, ha_buf, ha);
271 else
272 return 0;
273 }
274
ndisc_ops_fill_addr_option(const struct net_device * dev,struct sk_buff * skb,u8 icmp6_type)275 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
276 struct sk_buff *skb,
277 u8 icmp6_type)
278 {
279 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
280 icmp6_type != NDISC_REDIRECT)
281 dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
282 }
283
ndisc_ops_fill_redirect_addr_option(const struct net_device * dev,struct sk_buff * skb,const u8 * ha)284 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
285 struct sk_buff *skb,
286 const u8 *ha)
287 {
288 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
289 dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
290 }
291
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)292 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
293 struct net_device *dev,
294 const struct prefix_info *pinfo,
295 struct inet6_dev *in6_dev,
296 struct in6_addr *addr,
297 int addr_type, u32 addr_flags,
298 bool sllao, bool tokenized,
299 __u32 valid_lft,
300 u32 prefered_lft,
301 bool dev_addr_generated)
302 {
303 if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
304 dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
305 addr, addr_type,
306 addr_flags, sllao,
307 tokenized, valid_lft,
308 prefered_lft,
309 dev_addr_generated);
310 }
311 #endif
312
313 /*
314 * Return the padding between the option length and the start of the
315 * link addr. Currently only IP-over-InfiniBand needs this, although
316 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
317 * also need a pad of 2.
318 */
ndisc_addr_option_pad(unsigned short type)319 static inline int ndisc_addr_option_pad(unsigned short type)
320 {
321 switch (type) {
322 case ARPHRD_INFINIBAND: return 2;
323 default: return 0;
324 }
325 }
326
__ndisc_opt_addr_space(unsigned char addr_len,int pad)327 static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
328 {
329 return NDISC_OPT_SPACE(addr_len + pad);
330 }
331
332 #if IS_ENABLED(CONFIG_IPV6)
ndisc_opt_addr_space(struct net_device * dev,u8 icmp6_type)333 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
334 {
335 return __ndisc_opt_addr_space(dev->addr_len,
336 ndisc_addr_option_pad(dev->type)) +
337 ndisc_ops_opt_addr_space(dev, icmp6_type);
338 }
339
ndisc_redirect_opt_addr_space(struct net_device * dev,struct neighbour * neigh,u8 * ops_data_buf,u8 ** ops_data)340 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
341 struct neighbour *neigh,
342 u8 *ops_data_buf,
343 u8 **ops_data)
344 {
345 return __ndisc_opt_addr_space(dev->addr_len,
346 ndisc_addr_option_pad(dev->type)) +
347 ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
348 ops_data);
349 }
350 #endif
351
__ndisc_opt_addr_data(struct nd_opt_hdr * p,unsigned char addr_len,int prepad)352 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
353 unsigned char addr_len, int prepad)
354 {
355 u8 *lladdr = (u8 *)(p + 1);
356 int lladdrlen = p->nd_opt_len << 3;
357 if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
358 return NULL;
359 return lladdr + prepad;
360 }
361
ndisc_opt_addr_data(struct nd_opt_hdr * p,struct net_device * dev)362 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
363 struct net_device *dev)
364 {
365 return __ndisc_opt_addr_data(p, dev->addr_len,
366 ndisc_addr_option_pad(dev->type));
367 }
368
ndisc_hashfn(const void * pkey,const struct net_device * dev,__u32 * hash_rnd)369 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
370 {
371 const u32 *p32 = pkey;
372
373 return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
374 (p32[1] * hash_rnd[1]) +
375 (p32[2] * hash_rnd[2]) +
376 (p32[3] * hash_rnd[3]));
377 }
378
__ipv6_neigh_lookup_noref(struct net_device * dev,const void * pkey)379 static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
380 {
381 return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
382 }
383
__ipv6_neigh_lookup(struct net_device * dev,const void * pkey)384 static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
385 {
386 struct neighbour *n;
387
388 rcu_read_lock_bh();
389 n = __ipv6_neigh_lookup_noref(dev, pkey);
390 if (n && !refcount_inc_not_zero(&n->refcnt))
391 n = NULL;
392 rcu_read_unlock_bh();
393
394 return n;
395 }
396
__ipv6_confirm_neigh(struct net_device * dev,const void * pkey)397 static inline void __ipv6_confirm_neigh(struct net_device *dev,
398 const void *pkey)
399 {
400 struct neighbour *n;
401
402 rcu_read_lock_bh();
403 n = __ipv6_neigh_lookup_noref(dev, pkey);
404 if (n) {
405 unsigned long now = jiffies;
406
407 /* avoid dirtying neighbour */
408 if (n->confirmed != now)
409 n->confirmed = now;
410 }
411 rcu_read_unlock_bh();
412 }
413
414 int ndisc_init(void);
415 int ndisc_late_init(void);
416
417 void ndisc_late_cleanup(void);
418 void ndisc_cleanup(void);
419
420 int ndisc_rcv(struct sk_buff *skb);
421
422 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
423 const struct in6_addr *daddr, const struct in6_addr *saddr,
424 u64 nonce);
425
426 void ndisc_send_rs(struct net_device *dev,
427 const struct in6_addr *saddr, const struct in6_addr *daddr);
428 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
429 const struct in6_addr *solicited_addr,
430 bool router, bool solicited, bool override, bool inc_opt);
431
432 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
433
434 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
435 int dir);
436
437 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
438 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
439 struct ndisc_options *ndopts);
440
441 /*
442 * IGMP
443 */
444 int igmp6_init(void);
445 int igmp6_late_init(void);
446
447 void igmp6_cleanup(void);
448 void igmp6_late_cleanup(void);
449
450 int igmp6_event_query(struct sk_buff *skb);
451
452 int igmp6_event_report(struct sk_buff *skb);
453
454
455 #ifdef CONFIG_SYSCTL
456 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
457 void __user *buffer, size_t *lenp, loff_t *ppos);
458 int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
459 void __user *oldval, size_t __user *oldlenp,
460 void __user *newval, size_t newlen);
461 #endif
462
463 void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
464
465 #endif
466