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