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)
ndisc_ops_is_useropt(const struct net_device * dev,u8 nd_opt_type)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 
ndisc_ops_parse_options(const struct net_device * dev,struct nd_opt_hdr * nd_opt,struct ndisc_options * ndopts)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 
ndisc_ops_update(const struct net_device * dev,struct neighbour * n,u32 flags,u8 icmp6_type,const struct ndisc_options * ndopts)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 
ndisc_ops_opt_addr_space(const struct net_device * dev,u8 icmp6_type)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 
ndisc_ops_redirect_opt_addr_space(const struct net_device * dev,struct neighbour * neigh,u8 * ha_buf,u8 ** ha)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 
ndisc_ops_fill_addr_option(const struct net_device * dev,struct sk_buff * skb,u8 icmp6_type)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 
ndisc_ops_fill_redirect_addr_option(const struct net_device * dev,struct sk_buff * skb,const u8 * ha)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 
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)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  */
ndisc_addr_option_pad(unsigned short type)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 
__ndisc_opt_addr_space(unsigned char addr_len,int pad)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)
ndisc_opt_addr_space(struct net_device * dev,u8 icmp6_type)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 
ndisc_redirect_opt_addr_space(struct net_device * dev,struct neighbour * neigh,u8 * ops_data_buf,u8 ** ops_data)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 
__ndisc_opt_addr_data(struct nd_opt_hdr * p,unsigned char addr_len,int prepad)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 
ndisc_opt_addr_data(struct nd_opt_hdr * p,struct net_device * dev)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 
ndisc_hashfn(const void * pkey,const struct net_device * dev,__u32 * hash_rnd)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 
__ipv6_neigh_lookup_noref(struct net_device * dev,const void * pkey)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
__ipv6_neigh_lookup_noref_stub(struct net_device * dev,const void * pkey)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 
__ipv6_neigh_lookup(struct net_device * dev,const void * pkey)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_bh();
399 	n = __ipv6_neigh_lookup_noref(dev, pkey);
400 	if (n && !refcount_inc_not_zero(&n->refcnt))
401 		n = NULL;
402 	rcu_read_unlock_bh();
403 
404 	return n;
405 }
406 
__ipv6_confirm_neigh(struct net_device * dev,const void * pkey)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_bh();
413 	n = __ipv6_neigh_lookup_noref(dev, pkey);
414 	neigh_confirm(n);
415 	rcu_read_unlock_bh();
416 }
417 
__ipv6_confirm_neigh_stub(struct net_device * dev,const void * pkey)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_bh();
424 	n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
425 	neigh_confirm(n);
426 	rcu_read_unlock_bh();
427 }
428 
429 /* uses ipv6_stub and is meant for use outside of IPv6 core */
ip_neigh_gw6(struct net_device * dev,const void * addr)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 int 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(struct ctl_table *ctl, int write,
490 			       void *buffer, size_t *lenp, loff_t *ppos);
491 int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
492 				 void __user *oldval, size_t __user *oldlenp,
493 				 void __user *newval, size_t newlen);
494 #endif
495 
496 void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
497 
498 #endif
499