ndisc.h

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