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_MAX
45 };
46
47 #define MAX_RTR_SOLICITATION_DELAY HZ
48
49 #define ND_REACHABLE_TIME (30*HZ)
50 #define ND_RETRANS_TIMER HZ
51
52 #include <linux/compiler.h>
53 #include <linux/icmpv6.h>
54 #include <linux/in6.h>
55 #include <linux/types.h>
56 #include <linux/if_arp.h>
57 #include <linux/netdevice.h>
58 #include <linux/hash.h>
59
60 #include <net/neighbour.h>
61
62 /* Set to 3 to get tracing... */
63 #define ND_DEBUG 1
64
65 #define ND_PRINTK(val, level, fmt, ...) \
66 do { \
67 if (val <= ND_DEBUG) \
68 net_##level##_ratelimited(fmt, ##__VA_ARGS__); \
69 } while (0)
70
71 struct ctl_table;
72 struct inet6_dev;
73 struct net_device;
74 struct net_proto_family;
75 struct sk_buff;
76 struct prefix_info;
77
78 extern struct neigh_table nd_tbl;
79
80 struct nd_msg {
81 struct icmp6hdr icmph;
82 struct in6_addr target;
83 __u8 opt[0];
84 };
85
86 struct rs_msg {
87 struct icmp6hdr icmph;
88 __u8 opt[0];
89 };
90
91 struct ra_msg {
92 struct icmp6hdr icmph;
93 __be32 reachable_time;
94 __be32 retrans_timer;
95 };
96
97 struct rd_msg {
98 struct icmp6hdr icmph;
99 struct in6_addr target;
100 struct in6_addr dest;
101 __u8 opt[0];
102 };
103
104 struct nd_opt_hdr {
105 __u8 nd_opt_type;
106 __u8 nd_opt_len;
107 } __packed;
108
109 /* ND options */
110 struct ndisc_options {
111 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
112 #ifdef CONFIG_IPV6_ROUTE_INFO
113 struct nd_opt_hdr *nd_opts_ri;
114 struct nd_opt_hdr *nd_opts_ri_end;
115 #endif
116 struct nd_opt_hdr *nd_useropts;
117 struct nd_opt_hdr *nd_useropts_end;
118 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
119 struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
120 #endif
121 };
122
123 #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
124 #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR]
125 #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO]
126 #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END]
127 #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR]
128 #define nd_opts_mtu nd_opt_array[ND_OPT_MTU]
129 #define nd_opts_nonce nd_opt_array[ND_OPT_NONCE]
130 #define nd_802154_opts_src_lladdr nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
131 #define nd_802154_opts_tgt_lladdr nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
132
133 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
134
135 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
136 u8 *opt, int opt_len,
137 struct ndisc_options *ndopts);
138
139 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
140 int data_len, int pad);
141
142 #define NDISC_OPS_REDIRECT_DATA_SPACE 2
143
144 /*
145 * This structure defines the hooks for IPv6 neighbour discovery.
146 * The following hooks can be defined; unless noted otherwise, they are
147 * optional and can be filled with a null pointer.
148 *
149 * int (*is_useropt)(u8 nd_opt_type):
150 * This function is called when IPv6 decide RA userspace options. if
151 * this function returns 1 then the option given by nd_opt_type will
152 * be handled as userspace option additional to the IPv6 options.
153 *
154 * int (*parse_options)(const struct net_device *dev,
155 * struct nd_opt_hdr *nd_opt,
156 * struct ndisc_options *ndopts):
157 * This function is called while parsing ndisc ops and put each position
158 * as pointer into ndopts. If this function return unequal 0, then this
159 * function took care about the ndisc option, if 0 then the IPv6 ndisc
160 * option parser will take care about that option.
161 *
162 * void (*update)(const struct net_device *dev, struct neighbour *n,
163 * u32 flags, u8 icmp6_type,
164 * const struct ndisc_options *ndopts):
165 * This function is called when IPv6 ndisc updates the neighbour cache
166 * entry. Additional options which can be updated may be previously
167 * parsed by parse_opts callback and accessible over ndopts parameter.
168 *
169 * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
170 * struct neighbour *neigh, u8 *ha_buf,
171 * u8 **ha):
172 * This function is called when the necessary option space will be
173 * calculated before allocating a skb. The parameters neigh, ha_buf
174 * abd ha are available on NDISC_REDIRECT messages only.
175 *
176 * void (*fill_addr_option)(const struct net_device *dev,
177 * struct sk_buff *skb, u8 icmp6_type,
178 * const u8 *ha):
179 * This function is called when the skb will finally fill the option
180 * fields inside skb. NOTE: this callback should fill the option
181 * fields to the skb which are previously indicated by opt_space
182 * parameter. That means the decision to add such option should
183 * not lost between these two callbacks, e.g. protected by interface
184 * up state.
185 *
186 * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
187 * const struct prefix_info *pinfo,
188 * struct inet6_dev *in6_dev,
189 * struct in6_addr *addr,
190 * int addr_type, u32 addr_flags,
191 * bool sllao, bool tokenized,
192 * __u32 valid_lft, u32 prefered_lft,
193 * bool dev_addr_generated):
194 * This function is called when a RA messages is received with valid
195 * PIO option fields and an IPv6 address will be added to the interface
196 * for autoconfiguration. The parameter dev_addr_generated reports about
197 * if the address was based on dev->dev_addr or not. This can be used
198 * to add a second address if link-layer operates with two link layer
199 * addresses. E.g. 802.15.4 6LoWPAN.
200 */
201 struct ndisc_ops {
202 int (*is_useropt)(u8 nd_opt_type);
203 int (*parse_options)(const struct net_device *dev,
204 struct nd_opt_hdr *nd_opt,
205 struct ndisc_options *ndopts);
206 void (*update)(const struct net_device *dev, struct neighbour *n,
207 u32 flags, u8 icmp6_type,
208 const struct ndisc_options *ndopts);
209 int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
210 struct neighbour *neigh, u8 *ha_buf,
211 u8 **ha);
212 void (*fill_addr_option)(const struct net_device *dev,
213 struct sk_buff *skb, u8 icmp6_type,
214 const u8 *ha);
215 void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
216 const struct prefix_info *pinfo,
217 struct inet6_dev *in6_dev,
218 struct in6_addr *addr,
219 int addr_type, u32 addr_flags,
220 bool sllao, bool tokenized,
221 __u32 valid_lft, u32 prefered_lft,
222 bool dev_addr_generated);
223 };
224
225 #if IS_ENABLED(CONFIG_IPV6)
ndisc_ops_is_useropt(const struct net_device * dev,u8 nd_opt_type)226 static inline int ndisc_ops_is_useropt(const struct net_device *dev,
227 u8 nd_opt_type)
228 {
229 if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
230 return dev->ndisc_ops->is_useropt(nd_opt_type);
231 else
232 return 0;
233 }
234
ndisc_ops_parse_options(const struct net_device * dev,struct nd_opt_hdr * nd_opt,struct ndisc_options * ndopts)235 static inline int ndisc_ops_parse_options(const struct net_device *dev,
236 struct nd_opt_hdr *nd_opt,
237 struct ndisc_options *ndopts)
238 {
239 if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
240 return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
241 else
242 return 0;
243 }
244
ndisc_ops_update(const struct net_device * dev,struct neighbour * n,u32 flags,u8 icmp6_type,const struct ndisc_options * ndopts)245 static inline void ndisc_ops_update(const struct net_device *dev,
246 struct neighbour *n, u32 flags,
247 u8 icmp6_type,
248 const struct ndisc_options *ndopts)
249 {
250 if (dev->ndisc_ops && dev->ndisc_ops->update)
251 dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
252 }
253
ndisc_ops_opt_addr_space(const struct net_device * dev,u8 icmp6_type)254 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
255 u8 icmp6_type)
256 {
257 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
258 icmp6_type != NDISC_REDIRECT)
259 return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
260 NULL, NULL);
261 else
262 return 0;
263 }
264
ndisc_ops_redirect_opt_addr_space(const struct net_device * dev,struct neighbour * neigh,u8 * ha_buf,u8 ** ha)265 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
266 struct neighbour *neigh,
267 u8 *ha_buf, u8 **ha)
268 {
269 if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
270 return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
271 neigh, ha_buf, ha);
272 else
273 return 0;
274 }
275
ndisc_ops_fill_addr_option(const struct net_device * dev,struct sk_buff * skb,u8 icmp6_type)276 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
277 struct sk_buff *skb,
278 u8 icmp6_type)
279 {
280 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
281 icmp6_type != NDISC_REDIRECT)
282 dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
283 }
284
ndisc_ops_fill_redirect_addr_option(const struct net_device * dev,struct sk_buff * skb,const u8 * ha)285 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
286 struct sk_buff *skb,
287 const u8 *ha)
288 {
289 if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
290 dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
291 }
292
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)293 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
294 struct net_device *dev,
295 const struct prefix_info *pinfo,
296 struct inet6_dev *in6_dev,
297 struct in6_addr *addr,
298 int addr_type, u32 addr_flags,
299 bool sllao, bool tokenized,
300 __u32 valid_lft,
301 u32 prefered_lft,
302 bool dev_addr_generated)
303 {
304 if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
305 dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
306 addr, addr_type,
307 addr_flags, sllao,
308 tokenized, valid_lft,
309 prefered_lft,
310 dev_addr_generated);
311 }
312 #endif
313
314 /*
315 * Return the padding between the option length and the start of the
316 * link addr. Currently only IP-over-InfiniBand needs this, although
317 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
318 * also need a pad of 2.
319 */
ndisc_addr_option_pad(unsigned short type)320 static inline int ndisc_addr_option_pad(unsigned short type)
321 {
322 switch (type) {
323 case ARPHRD_INFINIBAND: return 2;
324 default: return 0;
325 }
326 }
327
__ndisc_opt_addr_space(unsigned char addr_len,int pad)328 static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
329 {
330 return NDISC_OPT_SPACE(addr_len + pad);
331 }
332
333 #if IS_ENABLED(CONFIG_IPV6)
ndisc_opt_addr_space(struct net_device * dev,u8 icmp6_type)334 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
335 {
336 return __ndisc_opt_addr_space(dev->addr_len,
337 ndisc_addr_option_pad(dev->type)) +
338 ndisc_ops_opt_addr_space(dev, icmp6_type);
339 }
340
ndisc_redirect_opt_addr_space(struct net_device * dev,struct neighbour * neigh,u8 * ops_data_buf,u8 ** ops_data)341 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
342 struct neighbour *neigh,
343 u8 *ops_data_buf,
344 u8 **ops_data)
345 {
346 return __ndisc_opt_addr_space(dev->addr_len,
347 ndisc_addr_option_pad(dev->type)) +
348 ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
349 ops_data);
350 }
351 #endif
352
__ndisc_opt_addr_data(struct nd_opt_hdr * p,unsigned char addr_len,int prepad)353 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
354 unsigned char addr_len, int prepad)
355 {
356 u8 *lladdr = (u8 *)(p + 1);
357 int lladdrlen = p->nd_opt_len << 3;
358 if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
359 return NULL;
360 return lladdr + prepad;
361 }
362
ndisc_opt_addr_data(struct nd_opt_hdr * p,struct net_device * dev)363 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
364 struct net_device *dev)
365 {
366 return __ndisc_opt_addr_data(p, dev->addr_len,
367 ndisc_addr_option_pad(dev->type));
368 }
369
ndisc_hashfn(const void * pkey,const struct net_device * dev,__u32 * hash_rnd)370 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
371 {
372 const u32 *p32 = pkey;
373
374 return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
375 (p32[1] * hash_rnd[1]) +
376 (p32[2] * hash_rnd[2]) +
377 (p32[3] * hash_rnd[3]));
378 }
379
__ipv6_neigh_lookup_noref(struct net_device * dev,const void * pkey)380 static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
381 {
382 return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
383 }
384
385 static inline
__ipv6_neigh_lookup_noref_stub(struct net_device * dev,const void * pkey)386 struct neighbour *__ipv6_neigh_lookup_noref_stub(struct net_device *dev,
387 const void *pkey)
388 {
389 return ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128,
390 ndisc_hashfn, pkey, dev);
391 }
392
__ipv6_neigh_lookup(struct net_device * dev,const void * pkey)393 static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
394 {
395 struct neighbour *n;
396
397 rcu_read_lock_bh();
398 n = __ipv6_neigh_lookup_noref(dev, pkey);
399 if (n && !refcount_inc_not_zero(&n->refcnt))
400 n = NULL;
401 rcu_read_unlock_bh();
402
403 return n;
404 }
405
__ipv6_confirm_neigh(struct net_device * dev,const void * pkey)406 static inline void __ipv6_confirm_neigh(struct net_device *dev,
407 const void *pkey)
408 {
409 struct neighbour *n;
410
411 rcu_read_lock_bh();
412 n = __ipv6_neigh_lookup_noref(dev, pkey);
413 if (n) {
414 unsigned long now = jiffies;
415
416 /* avoid dirtying neighbour */
417 if (n->confirmed != now)
418 n->confirmed = now;
419 }
420 rcu_read_unlock_bh();
421 }
422
__ipv6_confirm_neigh_stub(struct net_device * dev,const void * pkey)423 static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
424 const void *pkey)
425 {
426 struct neighbour *n;
427
428 rcu_read_lock_bh();
429 n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
430 if (n) {
431 unsigned long now = jiffies;
432
433 /* avoid dirtying neighbour */
434 if (n->confirmed != now)
435 n->confirmed = now;
436 }
437 rcu_read_unlock_bh();
438 }
439
440 /* uses ipv6_stub and is meant for use outside of IPv6 core */
ip_neigh_gw6(struct net_device * dev,const void * addr)441 static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
442 const void *addr)
443 {
444 struct neighbour *neigh;
445
446 neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
447 if (unlikely(!neigh))
448 neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
449
450 return neigh;
451 }
452
453 int ndisc_init(void);
454 int ndisc_late_init(void);
455
456 void ndisc_late_cleanup(void);
457 void ndisc_cleanup(void);
458
459 int ndisc_rcv(struct sk_buff *skb);
460
461 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
462 const struct in6_addr *daddr, const struct in6_addr *saddr,
463 u64 nonce);
464
465 void ndisc_send_rs(struct net_device *dev,
466 const struct in6_addr *saddr, const struct in6_addr *daddr);
467 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
468 const struct in6_addr *solicited_addr,
469 bool router, bool solicited, bool override, bool inc_opt);
470
471 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
472
473 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
474 int dir);
475
476 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
477 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
478 struct ndisc_options *ndopts);
479
480 /*
481 * IGMP
482 */
483 int igmp6_init(void);
484 int igmp6_late_init(void);
485
486 void igmp6_cleanup(void);
487 void igmp6_late_cleanup(void);
488
489 int igmp6_event_query(struct sk_buff *skb);
490
491 int igmp6_event_report(struct sk_buff *skb);
492
493
494 #ifdef CONFIG_SYSCTL
495 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
496 void __user *buffer, size_t *lenp, loff_t *ppos);
497 int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
498 void __user *oldval, size_t __user *oldlenp,
499 void __user *newval, size_t newlen);
500 #endif
501
502 void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
503
504 #endif
505
