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v5.4
  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 *	Linux INET6 implementation 
  4 *
  5 *	Authors:
  6 *	Pedro Roque		<roque@di.fc.ul.pt>	
  7 */
  8
  9#ifndef _IP6_FIB_H
 10#define _IP6_FIB_H
 11
 12#include <linux/ipv6_route.h>
 13#include <linux/rtnetlink.h>
 14#include <linux/spinlock.h>
 15#include <linux/notifier.h>
 16#include <net/dst.h>
 17#include <net/flow.h>
 18#include <net/ip_fib.h>
 19#include <net/netlink.h>
 20#include <net/inetpeer.h>
 21#include <net/fib_notifier.h>
 
 
 22
 23#ifdef CONFIG_IPV6_MULTIPLE_TABLES
 24#define FIB6_TABLE_HASHSZ 256
 25#else
 26#define FIB6_TABLE_HASHSZ 1
 27#endif
 28
 29#define RT6_DEBUG 2
 30
 31#if RT6_DEBUG >= 3
 32#define RT6_TRACE(x...) pr_debug(x)
 33#else
 34#define RT6_TRACE(x...) do { ; } while (0)
 35#endif
 36
 37struct rt6_info;
 38struct fib6_info;
 39
 40struct fib6_config {
 41	u32		fc_table;
 42	u32		fc_metric;
 43	int		fc_dst_len;
 44	int		fc_src_len;
 45	int		fc_ifindex;
 46	u32		fc_flags;
 47	u32		fc_protocol;
 48	u16		fc_type;        /* only 8 bits are used */
 49	u16		fc_delete_all_nh : 1,
 50			fc_ignore_dev_down:1,
 51			__unused : 14;
 52	u32		fc_nh_id;
 53
 54	struct in6_addr	fc_dst;
 55	struct in6_addr	fc_src;
 56	struct in6_addr	fc_prefsrc;
 57	struct in6_addr	fc_gateway;
 58
 59	unsigned long	fc_expires;
 60	struct nlattr	*fc_mx;
 61	int		fc_mx_len;
 62	int		fc_mp_len;
 63	struct nlattr	*fc_mp;
 64
 65	struct nl_info	fc_nlinfo;
 66	struct nlattr	*fc_encap;
 67	u16		fc_encap_type;
 
 68};
 69
 70struct fib6_node {
 71	struct fib6_node __rcu	*parent;
 72	struct fib6_node __rcu	*left;
 73	struct fib6_node __rcu	*right;
 74#ifdef CONFIG_IPV6_SUBTREES
 75	struct fib6_node __rcu	*subtree;
 76#endif
 77	struct fib6_info __rcu	*leaf;
 78
 79	__u16			fn_bit;		/* bit key */
 80	__u16			fn_flags;
 81	int			fn_sernum;
 82	struct fib6_info __rcu	*rr_ptr;
 83	struct rcu_head		rcu;
 84};
 85
 86struct fib6_gc_args {
 87	int			timeout;
 88	int			more;
 89};
 90
 91#ifndef CONFIG_IPV6_SUBTREES
 92#define FIB6_SUBTREE(fn)	NULL
 
 
 
 
 
 
 
 
 
 93#else
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 94#define FIB6_SUBTREE(fn)	(rcu_dereference_protected((fn)->subtree, 1))
 95#endif
 96
 97/*
 98 *	routing information
 99 *
100 */
101
102struct rt6key {
103	struct in6_addr	addr;
104	int		plen;
105};
106
107struct fib6_table;
108
109struct rt6_exception_bucket {
110	struct hlist_head	chain;
111	int			depth;
112};
113
114struct rt6_exception {
115	struct hlist_node	hlist;
116	struct rt6_info		*rt6i;
117	unsigned long		stamp;
118	struct rcu_head		rcu;
119};
120
121#define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
122#define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
123#define FIB6_MAX_DEPTH 5
124
125struct fib6_nh {
126	struct fib_nh_common	nh_common;
127
128#ifdef CONFIG_IPV6_ROUTER_PREF
129	unsigned long		last_probe;
130#endif
131
132	struct rt6_info * __percpu *rt6i_pcpu;
133	struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
134};
135
136struct fib6_info {
137	struct fib6_table		*fib6_table;
138	struct fib6_info __rcu		*fib6_next;
139	struct fib6_node __rcu		*fib6_node;
140
141	/* Multipath routes:
142	 * siblings is a list of fib6_info that have the the same metric/weight,
143	 * destination, but not the same gateway. nsiblings is just a cache
144	 * to speed up lookup.
145	 */
146	union {
147		struct list_head	fib6_siblings;
148		struct list_head	nh_list;
149	};
150	unsigned int			fib6_nsiblings;
151
152	refcount_t			fib6_ref;
153	unsigned long			expires;
154	struct dst_metrics		*fib6_metrics;
155#define fib6_pmtu		fib6_metrics->metrics[RTAX_MTU-1]
156
157	struct rt6key			fib6_dst;
158	u32				fib6_flags;
159	struct rt6key			fib6_src;
160	struct rt6key			fib6_prefsrc;
161
162	u32				fib6_metric;
163	u8				fib6_protocol;
164	u8				fib6_type;
 
 
 
 
 
165	u8				should_flush:1,
166					dst_nocount:1,
167					dst_nopolicy:1,
168					dst_host:1,
169					fib6_destroying:1,
170					unused:3;
171
172	struct rcu_head			rcu;
173	struct nexthop			*nh;
174	struct fib6_nh			fib6_nh[0];
175};
176
177struct rt6_info {
178	struct dst_entry		dst;
179	struct fib6_info __rcu		*from;
 
180
181	struct rt6key			rt6i_dst;
182	struct rt6key			rt6i_src;
183	struct in6_addr			rt6i_gateway;
184	struct inet6_dev		*rt6i_idev;
185	u32				rt6i_flags;
186
187	struct list_head		rt6i_uncached;
188	struct uncached_list		*rt6i_uncached_list;
189
190	/* more non-fragment space at head required */
191	unsigned short			rt6i_nfheader_len;
192};
193
194struct fib6_result {
195	struct fib6_nh		*nh;
196	struct fib6_info	*f6i;
197	u32			fib6_flags;
198	u8			fib6_type;
199	struct rt6_info		*rt6;
200};
201
202#define for_each_fib6_node_rt_rcu(fn)					\
203	for (rt = rcu_dereference((fn)->leaf); rt;			\
204	     rt = rcu_dereference(rt->fib6_next))
205
206#define for_each_fib6_walker_rt(w)					\
207	for (rt = (w)->leaf; rt;					\
208	     rt = rcu_dereference_protected(rt->fib6_next, 1))
209
210static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
211{
212	return ((struct rt6_info *)dst)->rt6i_idev;
213}
214
 
 
 
 
 
215static inline void fib6_clean_expires(struct fib6_info *f6i)
216{
217	f6i->fib6_flags &= ~RTF_EXPIRES;
218	f6i->expires = 0;
219}
220
221static inline void fib6_set_expires(struct fib6_info *f6i,
222				    unsigned long expires)
223{
224	f6i->expires = expires;
225	f6i->fib6_flags |= RTF_EXPIRES;
226}
227
228static inline bool fib6_check_expired(const struct fib6_info *f6i)
229{
230	if (f6i->fib6_flags & RTF_EXPIRES)
231		return time_after(jiffies, f6i->expires);
232	return false;
233}
234
235/* Function to safely get fn->sernum for passed in rt
236 * and store result in passed in cookie.
237 * Return true if we can get cookie safely
238 * Return false if not
239 */
240static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
241					u32 *cookie)
242{
243	struct fib6_node *fn;
244	bool status = false;
245
246	fn = rcu_dereference(f6i->fib6_node);
247
248	if (fn) {
249		*cookie = fn->fn_sernum;
250		/* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
251		smp_rmb();
252		status = true;
253	}
254
255	return status;
256}
257
258static inline u32 rt6_get_cookie(const struct rt6_info *rt)
259{
260	struct fib6_info *from;
261	u32 cookie = 0;
262
 
 
 
263	rcu_read_lock();
264
265	from = rcu_dereference(rt->from);
266	if (from)
267		fib6_get_cookie_safe(from, &cookie);
268
269	rcu_read_unlock();
270
271	return cookie;
272}
273
274static inline void ip6_rt_put(struct rt6_info *rt)
275{
276	/* dst_release() accepts a NULL parameter.
277	 * We rely on dst being first structure in struct rt6_info
278	 */
279	BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
280	dst_release(&rt->dst);
281}
282
283struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
284void fib6_info_destroy_rcu(struct rcu_head *head);
285
286static inline void fib6_info_hold(struct fib6_info *f6i)
287{
288	refcount_inc(&f6i->fib6_ref);
289}
290
291static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
292{
293	return refcount_inc_not_zero(&f6i->fib6_ref);
294}
295
296static inline void fib6_info_release(struct fib6_info *f6i)
297{
298	if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
299		call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
300}
301
302enum fib6_walk_state {
303#ifdef CONFIG_IPV6_SUBTREES
304	FWS_S,
305#endif
306	FWS_L,
307	FWS_R,
308	FWS_C,
309	FWS_U
310};
311
312struct fib6_walker {
313	struct list_head lh;
314	struct fib6_node *root, *node;
315	struct fib6_info *leaf;
316	enum fib6_walk_state state;
317	unsigned int skip;
318	unsigned int count;
319	unsigned int skip_in_node;
320	int (*func)(struct fib6_walker *);
321	void *args;
322};
323
324struct rt6_statistics {
325	__u32		fib_nodes;		/* all fib6 nodes */
326	__u32		fib_route_nodes;	/* intermediate nodes */
327	__u32		fib_rt_entries;		/* rt entries in fib table */
328	__u32		fib_rt_cache;		/* cached rt entries in exception table */
329	__u32		fib_discarded_routes;	/* total number of routes delete */
330
331	/* The following stats are not protected by any lock */
332	atomic_t	fib_rt_alloc;		/* total number of routes alloced */
333	atomic_t	fib_rt_uncache;		/* rt entries in uncached list */
334};
335
336#define RTN_TL_ROOT	0x0001
337#define RTN_ROOT	0x0002		/* tree root node		*/
338#define RTN_RTINFO	0x0004		/* node with valid routing info	*/
339
340/*
341 *	priority levels (or metrics)
342 *
343 */
344
345
346struct fib6_table {
347	struct hlist_node	tb6_hlist;
348	u32			tb6_id;
349	spinlock_t		tb6_lock;
350	struct fib6_node	tb6_root;
351	struct inet_peer_base	tb6_peers;
352	unsigned int		flags;
353	unsigned int		fib_seq;
354#define RT6_TABLE_HAS_DFLT_ROUTER	BIT(0)
355};
356
357#define RT6_TABLE_UNSPEC	RT_TABLE_UNSPEC
358#define RT6_TABLE_MAIN		RT_TABLE_MAIN
359#define RT6_TABLE_DFLT		RT6_TABLE_MAIN
360#define RT6_TABLE_INFO		RT6_TABLE_MAIN
361#define RT6_TABLE_PREFIX	RT6_TABLE_MAIN
362
363#ifdef CONFIG_IPV6_MULTIPLE_TABLES
364#define FIB6_TABLE_MIN		1
365#define FIB6_TABLE_MAX		RT_TABLE_MAX
366#define RT6_TABLE_LOCAL		RT_TABLE_LOCAL
367#else
368#define FIB6_TABLE_MIN		RT_TABLE_MAIN
369#define FIB6_TABLE_MAX		FIB6_TABLE_MIN
370#define RT6_TABLE_LOCAL		RT6_TABLE_MAIN
371#endif
372
373typedef struct rt6_info *(*pol_lookup_t)(struct net *,
374					 struct fib6_table *,
375					 struct flowi6 *,
376					 const struct sk_buff *, int);
377
378struct fib6_entry_notifier_info {
379	struct fib_notifier_info info; /* must be first */
380	struct fib6_info *rt;
381	unsigned int nsiblings;
382};
383
384/*
385 *	exported functions
386 */
387
388struct fib6_table *fib6_get_table(struct net *net, u32 id);
389struct fib6_table *fib6_new_table(struct net *net, u32 id);
390struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
391				   const struct sk_buff *skb,
392				   int flags, pol_lookup_t lookup);
393
394/* called with rcu lock held; can return error pointer
395 * caller needs to select path
396 */
397int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
398		struct fib6_result *res, int flags);
399
400/* called with rcu lock held; caller needs to select path */
401int fib6_table_lookup(struct net *net, struct fib6_table *table,
402		      int oif, struct flowi6 *fl6, struct fib6_result *res,
403		      int strict);
404
405void fib6_select_path(const struct net *net, struct fib6_result *res,
406		      struct flowi6 *fl6, int oif, bool have_oif_match,
407		      const struct sk_buff *skb, int strict);
408struct fib6_node *fib6_node_lookup(struct fib6_node *root,
409				   const struct in6_addr *daddr,
410				   const struct in6_addr *saddr);
411
412struct fib6_node *fib6_locate(struct fib6_node *root,
413			      const struct in6_addr *daddr, int dst_len,
414			      const struct in6_addr *saddr, int src_len,
415			      bool exact_match);
416
417void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
418		    void *arg);
419void fib6_clean_all_skip_notify(struct net *net,
420				int (*func)(struct fib6_info *, void *arg),
421				void *arg);
422
423int fib6_add(struct fib6_node *root, struct fib6_info *rt,
424	     struct nl_info *info, struct netlink_ext_ack *extack);
425int fib6_del(struct fib6_info *rt, struct nl_info *info);
426
427static inline
428void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
429{
430	const struct fib6_info *from;
431
432	rcu_read_lock();
433
434	from = rcu_dereference(rt->from);
435	if (from) {
436		*addr = from->fib6_prefsrc.addr;
437	} else {
438		struct in6_addr in6_zero = {};
439
440		*addr = in6_zero;
441	}
442
443	rcu_read_unlock();
444}
445
446int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
447		 struct fib6_config *cfg, gfp_t gfp_flags,
448		 struct netlink_ext_ack *extack);
449void fib6_nh_release(struct fib6_nh *fib6_nh);
 
450
451int call_fib6_entry_notifiers(struct net *net,
452			      enum fib_event_type event_type,
453			      struct fib6_info *rt,
454			      struct netlink_ext_ack *extack);
455int call_fib6_multipath_entry_notifiers(struct net *net,
456					enum fib_event_type event_type,
457					struct fib6_info *rt,
458					unsigned int nsiblings,
459					struct netlink_ext_ack *extack);
 
460void fib6_rt_update(struct net *net, struct fib6_info *rt,
461		    struct nl_info *info);
462void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
463		     unsigned int flags);
464
465void fib6_run_gc(unsigned long expires, struct net *net, bool force);
466
467void fib6_gc_cleanup(void);
468
469int fib6_init(void);
470
471struct ipv6_route_iter {
472	struct seq_net_private p;
473	struct fib6_walker w;
474	loff_t skip;
475	struct fib6_table *tbl;
476	int sernum;
477};
478
479extern const struct seq_operations ipv6_route_seq_ops;
480
481int call_fib6_notifier(struct notifier_block *nb, struct net *net,
482		       enum fib_event_type event_type,
483		       struct fib_notifier_info *info);
484int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
485			struct fib_notifier_info *info);
486
487int __net_init fib6_notifier_init(struct net *net);
488void __net_exit fib6_notifier_exit(struct net *net);
489
490unsigned int fib6_tables_seq_read(struct net *net);
491int fib6_tables_dump(struct net *net, struct notifier_block *nb);
 
492
493void fib6_update_sernum(struct net *net, struct fib6_info *rt);
494void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
495void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
496
497void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
498static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
499{
500	return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
501}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
502
503#ifdef CONFIG_IPV6_MULTIPLE_TABLES
 
 
 
 
 
504int fib6_rules_init(void);
505void fib6_rules_cleanup(void);
506bool fib6_rule_default(const struct fib_rule *rule);
507int fib6_rules_dump(struct net *net, struct notifier_block *nb);
 
508unsigned int fib6_rules_seq_read(struct net *net);
509
510static inline bool fib6_rules_early_flow_dissect(struct net *net,
511						 struct sk_buff *skb,
512						 struct flowi6 *fl6,
513						 struct flow_keys *flkeys)
514{
515	unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
516
517	if (!net->ipv6.fib6_rules_require_fldissect)
518		return false;
519
520	skb_flow_dissect_flow_keys(skb, flkeys, flag);
521	fl6->fl6_sport = flkeys->ports.src;
522	fl6->fl6_dport = flkeys->ports.dst;
523	fl6->flowi6_proto = flkeys->basic.ip_proto;
524
525	return true;
526}
527#else
 
 
 
 
528static inline int               fib6_rules_init(void)
529{
530	return 0;
531}
532static inline void              fib6_rules_cleanup(void)
533{
534	return ;
535}
536static inline bool fib6_rule_default(const struct fib_rule *rule)
537{
538	return true;
539}
540static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb)
 
541{
542	return 0;
543}
544static inline unsigned int fib6_rules_seq_read(struct net *net)
545{
546	return 0;
547}
548static inline bool fib6_rules_early_flow_dissect(struct net *net,
549						 struct sk_buff *skb,
550						 struct flowi6 *fl6,
551						 struct flow_keys *flkeys)
552{
553	return false;
554}
555#endif
556#endif
v6.2
  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 *	Linux INET6 implementation 
  4 *
  5 *	Authors:
  6 *	Pedro Roque		<roque@di.fc.ul.pt>	
  7 */
  8
  9#ifndef _IP6_FIB_H
 10#define _IP6_FIB_H
 11
 12#include <linux/ipv6_route.h>
 13#include <linux/rtnetlink.h>
 14#include <linux/spinlock.h>
 15#include <linux/notifier.h>
 16#include <net/dst.h>
 17#include <net/flow.h>
 18#include <net/ip_fib.h>
 19#include <net/netlink.h>
 20#include <net/inetpeer.h>
 21#include <net/fib_notifier.h>
 22#include <linux/indirect_call_wrapper.h>
 23#include <uapi/linux/bpf.h>
 24
 25#ifdef CONFIG_IPV6_MULTIPLE_TABLES
 26#define FIB6_TABLE_HASHSZ 256
 27#else
 28#define FIB6_TABLE_HASHSZ 1
 29#endif
 30
 31#define RT6_DEBUG 2
 32
 33#if RT6_DEBUG >= 3
 34#define RT6_TRACE(x...) pr_debug(x)
 35#else
 36#define RT6_TRACE(x...) do { ; } while (0)
 37#endif
 38
 39struct rt6_info;
 40struct fib6_info;
 41
 42struct fib6_config {
 43	u32		fc_table;
 44	u32		fc_metric;
 45	int		fc_dst_len;
 46	int		fc_src_len;
 47	int		fc_ifindex;
 48	u32		fc_flags;
 49	u32		fc_protocol;
 50	u16		fc_type;        /* only 8 bits are used */
 51	u16		fc_delete_all_nh : 1,
 52			fc_ignore_dev_down:1,
 53			__unused : 14;
 54	u32		fc_nh_id;
 55
 56	struct in6_addr	fc_dst;
 57	struct in6_addr	fc_src;
 58	struct in6_addr	fc_prefsrc;
 59	struct in6_addr	fc_gateway;
 60
 61	unsigned long	fc_expires;
 62	struct nlattr	*fc_mx;
 63	int		fc_mx_len;
 64	int		fc_mp_len;
 65	struct nlattr	*fc_mp;
 66
 67	struct nl_info	fc_nlinfo;
 68	struct nlattr	*fc_encap;
 69	u16		fc_encap_type;
 70	bool		fc_is_fdb;
 71};
 72
 73struct fib6_node {
 74	struct fib6_node __rcu	*parent;
 75	struct fib6_node __rcu	*left;
 76	struct fib6_node __rcu	*right;
 77#ifdef CONFIG_IPV6_SUBTREES
 78	struct fib6_node __rcu	*subtree;
 79#endif
 80	struct fib6_info __rcu	*leaf;
 81
 82	__u16			fn_bit;		/* bit key */
 83	__u16			fn_flags;
 84	int			fn_sernum;
 85	struct fib6_info __rcu	*rr_ptr;
 86	struct rcu_head		rcu;
 87};
 88
 89struct fib6_gc_args {
 90	int			timeout;
 91	int			more;
 92};
 93
 94#ifndef CONFIG_IPV6_SUBTREES
 95#define FIB6_SUBTREE(fn)	NULL
 96
 97static inline bool fib6_routes_require_src(const struct net *net)
 98{
 99	return false;
100}
101
102static inline void fib6_routes_require_src_inc(struct net *net) {}
103static inline void fib6_routes_require_src_dec(struct net *net) {}
104
105#else
106
107static inline bool fib6_routes_require_src(const struct net *net)
108{
109	return net->ipv6.fib6_routes_require_src > 0;
110}
111
112static inline void fib6_routes_require_src_inc(struct net *net)
113{
114	net->ipv6.fib6_routes_require_src++;
115}
116
117static inline void fib6_routes_require_src_dec(struct net *net)
118{
119	net->ipv6.fib6_routes_require_src--;
120}
121
122#define FIB6_SUBTREE(fn)	(rcu_dereference_protected((fn)->subtree, 1))
123#endif
124
125/*
126 *	routing information
127 *
128 */
129
130struct rt6key {
131	struct in6_addr	addr;
132	int		plen;
133};
134
135struct fib6_table;
136
137struct rt6_exception_bucket {
138	struct hlist_head	chain;
139	int			depth;
140};
141
142struct rt6_exception {
143	struct hlist_node	hlist;
144	struct rt6_info		*rt6i;
145	unsigned long		stamp;
146	struct rcu_head		rcu;
147};
148
149#define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
150#define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
151#define FIB6_MAX_DEPTH 5
152
153struct fib6_nh {
154	struct fib_nh_common	nh_common;
155
156#ifdef CONFIG_IPV6_ROUTER_PREF
157	unsigned long		last_probe;
158#endif
159
160	struct rt6_info * __percpu *rt6i_pcpu;
161	struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
162};
163
164struct fib6_info {
165	struct fib6_table		*fib6_table;
166	struct fib6_info __rcu		*fib6_next;
167	struct fib6_node __rcu		*fib6_node;
168
169	/* Multipath routes:
170	 * siblings is a list of fib6_info that have the same metric/weight,
171	 * destination, but not the same gateway. nsiblings is just a cache
172	 * to speed up lookup.
173	 */
174	union {
175		struct list_head	fib6_siblings;
176		struct list_head	nh_list;
177	};
178	unsigned int			fib6_nsiblings;
179
180	refcount_t			fib6_ref;
181	unsigned long			expires;
182	struct dst_metrics		*fib6_metrics;
183#define fib6_pmtu		fib6_metrics->metrics[RTAX_MTU-1]
184
185	struct rt6key			fib6_dst;
186	u32				fib6_flags;
187	struct rt6key			fib6_src;
188	struct rt6key			fib6_prefsrc;
189
190	u32				fib6_metric;
191	u8				fib6_protocol;
192	u8				fib6_type;
193
194	u8				offload;
195	u8				trap;
196	u8				offload_failed;
197
198	u8				should_flush:1,
199					dst_nocount:1,
200					dst_nopolicy:1,
 
201					fib6_destroying:1,
202					unused:4;
203
204	struct rcu_head			rcu;
205	struct nexthop			*nh;
206	struct fib6_nh			fib6_nh[];
207};
208
209struct rt6_info {
210	struct dst_entry		dst;
211	struct fib6_info __rcu		*from;
212	int				sernum;
213
214	struct rt6key			rt6i_dst;
215	struct rt6key			rt6i_src;
216	struct in6_addr			rt6i_gateway;
217	struct inet6_dev		*rt6i_idev;
218	u32				rt6i_flags;
219
220	struct list_head		rt6i_uncached;
221	struct uncached_list		*rt6i_uncached_list;
222
223	/* more non-fragment space at head required */
224	unsigned short			rt6i_nfheader_len;
225};
226
227struct fib6_result {
228	struct fib6_nh		*nh;
229	struct fib6_info	*f6i;
230	u32			fib6_flags;
231	u8			fib6_type;
232	struct rt6_info		*rt6;
233};
234
235#define for_each_fib6_node_rt_rcu(fn)					\
236	for (rt = rcu_dereference((fn)->leaf); rt;			\
237	     rt = rcu_dereference(rt->fib6_next))
238
239#define for_each_fib6_walker_rt(w)					\
240	for (rt = (w)->leaf; rt;					\
241	     rt = rcu_dereference_protected(rt->fib6_next, 1))
242
243static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
244{
245	return ((struct rt6_info *)dst)->rt6i_idev;
246}
247
248static inline bool fib6_requires_src(const struct fib6_info *rt)
249{
250	return rt->fib6_src.plen > 0;
251}
252
253static inline void fib6_clean_expires(struct fib6_info *f6i)
254{
255	f6i->fib6_flags &= ~RTF_EXPIRES;
256	f6i->expires = 0;
257}
258
259static inline void fib6_set_expires(struct fib6_info *f6i,
260				    unsigned long expires)
261{
262	f6i->expires = expires;
263	f6i->fib6_flags |= RTF_EXPIRES;
264}
265
266static inline bool fib6_check_expired(const struct fib6_info *f6i)
267{
268	if (f6i->fib6_flags & RTF_EXPIRES)
269		return time_after(jiffies, f6i->expires);
270	return false;
271}
272
273/* Function to safely get fn->fn_sernum for passed in rt
274 * and store result in passed in cookie.
275 * Return true if we can get cookie safely
276 * Return false if not
277 */
278static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
279					u32 *cookie)
280{
281	struct fib6_node *fn;
282	bool status = false;
283
284	fn = rcu_dereference(f6i->fib6_node);
285
286	if (fn) {
287		*cookie = READ_ONCE(fn->fn_sernum);
288		/* pairs with smp_wmb() in __fib6_update_sernum_upto_root() */
289		smp_rmb();
290		status = true;
291	}
292
293	return status;
294}
295
296static inline u32 rt6_get_cookie(const struct rt6_info *rt)
297{
298	struct fib6_info *from;
299	u32 cookie = 0;
300
301	if (rt->sernum)
302		return rt->sernum;
303
304	rcu_read_lock();
305
306	from = rcu_dereference(rt->from);
307	if (from)
308		fib6_get_cookie_safe(from, &cookie);
309
310	rcu_read_unlock();
311
312	return cookie;
313}
314
315static inline void ip6_rt_put(struct rt6_info *rt)
316{
317	/* dst_release() accepts a NULL parameter.
318	 * We rely on dst being first structure in struct rt6_info
319	 */
320	BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
321	dst_release(&rt->dst);
322}
323
324struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
325void fib6_info_destroy_rcu(struct rcu_head *head);
326
327static inline void fib6_info_hold(struct fib6_info *f6i)
328{
329	refcount_inc(&f6i->fib6_ref);
330}
331
332static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
333{
334	return refcount_inc_not_zero(&f6i->fib6_ref);
335}
336
337static inline void fib6_info_release(struct fib6_info *f6i)
338{
339	if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
340		call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
341}
342
343enum fib6_walk_state {
344#ifdef CONFIG_IPV6_SUBTREES
345	FWS_S,
346#endif
347	FWS_L,
348	FWS_R,
349	FWS_C,
350	FWS_U
351};
352
353struct fib6_walker {
354	struct list_head lh;
355	struct fib6_node *root, *node;
356	struct fib6_info *leaf;
357	enum fib6_walk_state state;
358	unsigned int skip;
359	unsigned int count;
360	unsigned int skip_in_node;
361	int (*func)(struct fib6_walker *);
362	void *args;
363};
364
365struct rt6_statistics {
366	__u32		fib_nodes;		/* all fib6 nodes */
367	__u32		fib_route_nodes;	/* intermediate nodes */
368	__u32		fib_rt_entries;		/* rt entries in fib table */
369	__u32		fib_rt_cache;		/* cached rt entries in exception table */
370	__u32		fib_discarded_routes;	/* total number of routes delete */
371
372	/* The following stat is not protected by any lock */
373	atomic_t	fib_rt_alloc;		/* total number of routes alloced */
 
374};
375
376#define RTN_TL_ROOT	0x0001
377#define RTN_ROOT	0x0002		/* tree root node		*/
378#define RTN_RTINFO	0x0004		/* node with valid routing info	*/
379
380/*
381 *	priority levels (or metrics)
382 *
383 */
384
385
386struct fib6_table {
387	struct hlist_node	tb6_hlist;
388	u32			tb6_id;
389	spinlock_t		tb6_lock;
390	struct fib6_node	tb6_root;
391	struct inet_peer_base	tb6_peers;
392	unsigned int		flags;
393	unsigned int		fib_seq;
394#define RT6_TABLE_HAS_DFLT_ROUTER	BIT(0)
395};
396
397#define RT6_TABLE_UNSPEC	RT_TABLE_UNSPEC
398#define RT6_TABLE_MAIN		RT_TABLE_MAIN
399#define RT6_TABLE_DFLT		RT6_TABLE_MAIN
400#define RT6_TABLE_INFO		RT6_TABLE_MAIN
401#define RT6_TABLE_PREFIX	RT6_TABLE_MAIN
402
403#ifdef CONFIG_IPV6_MULTIPLE_TABLES
404#define FIB6_TABLE_MIN		1
405#define FIB6_TABLE_MAX		RT_TABLE_MAX
406#define RT6_TABLE_LOCAL		RT_TABLE_LOCAL
407#else
408#define FIB6_TABLE_MIN		RT_TABLE_MAIN
409#define FIB6_TABLE_MAX		FIB6_TABLE_MIN
410#define RT6_TABLE_LOCAL		RT6_TABLE_MAIN
411#endif
412
413typedef struct rt6_info *(*pol_lookup_t)(struct net *,
414					 struct fib6_table *,
415					 struct flowi6 *,
416					 const struct sk_buff *, int);
417
418struct fib6_entry_notifier_info {
419	struct fib_notifier_info info; /* must be first */
420	struct fib6_info *rt;
421	unsigned int nsiblings;
422};
423
424/*
425 *	exported functions
426 */
427
428struct fib6_table *fib6_get_table(struct net *net, u32 id);
429struct fib6_table *fib6_new_table(struct net *net, u32 id);
430struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
431				   const struct sk_buff *skb,
432				   int flags, pol_lookup_t lookup);
433
434/* called with rcu lock held; can return error pointer
435 * caller needs to select path
436 */
437int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
438		struct fib6_result *res, int flags);
439
440/* called with rcu lock held; caller needs to select path */
441int fib6_table_lookup(struct net *net, struct fib6_table *table,
442		      int oif, struct flowi6 *fl6, struct fib6_result *res,
443		      int strict);
444
445void fib6_select_path(const struct net *net, struct fib6_result *res,
446		      struct flowi6 *fl6, int oif, bool have_oif_match,
447		      const struct sk_buff *skb, int strict);
448struct fib6_node *fib6_node_lookup(struct fib6_node *root,
449				   const struct in6_addr *daddr,
450				   const struct in6_addr *saddr);
451
452struct fib6_node *fib6_locate(struct fib6_node *root,
453			      const struct in6_addr *daddr, int dst_len,
454			      const struct in6_addr *saddr, int src_len,
455			      bool exact_match);
456
457void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
458		    void *arg);
459void fib6_clean_all_skip_notify(struct net *net,
460				int (*func)(struct fib6_info *, void *arg),
461				void *arg);
462
463int fib6_add(struct fib6_node *root, struct fib6_info *rt,
464	     struct nl_info *info, struct netlink_ext_ack *extack);
465int fib6_del(struct fib6_info *rt, struct nl_info *info);
466
467static inline
468void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
469{
470	const struct fib6_info *from;
471
472	rcu_read_lock();
473
474	from = rcu_dereference(rt->from);
475	if (from) {
476		*addr = from->fib6_prefsrc.addr;
477	} else {
478		struct in6_addr in6_zero = {};
479
480		*addr = in6_zero;
481	}
482
483	rcu_read_unlock();
484}
485
486int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
487		 struct fib6_config *cfg, gfp_t gfp_flags,
488		 struct netlink_ext_ack *extack);
489void fib6_nh_release(struct fib6_nh *fib6_nh);
490void fib6_nh_release_dsts(struct fib6_nh *fib6_nh);
491
492int call_fib6_entry_notifiers(struct net *net,
493			      enum fib_event_type event_type,
494			      struct fib6_info *rt,
495			      struct netlink_ext_ack *extack);
496int call_fib6_multipath_entry_notifiers(struct net *net,
497					enum fib_event_type event_type,
498					struct fib6_info *rt,
499					unsigned int nsiblings,
500					struct netlink_ext_ack *extack);
501int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt);
502void fib6_rt_update(struct net *net, struct fib6_info *rt,
503		    struct nl_info *info);
504void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
505		     unsigned int flags);
506
507void fib6_run_gc(unsigned long expires, struct net *net, bool force);
508
509void fib6_gc_cleanup(void);
510
511int fib6_init(void);
512
513struct ipv6_route_iter {
514	struct seq_net_private p;
515	struct fib6_walker w;
516	loff_t skip;
517	struct fib6_table *tbl;
518	int sernum;
519};
520
521extern const struct seq_operations ipv6_route_seq_ops;
522
523int call_fib6_notifier(struct notifier_block *nb,
524		       enum fib_event_type event_type,
525		       struct fib_notifier_info *info);
526int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
527			struct fib_notifier_info *info);
528
529int __net_init fib6_notifier_init(struct net *net);
530void __net_exit fib6_notifier_exit(struct net *net);
531
532unsigned int fib6_tables_seq_read(struct net *net);
533int fib6_tables_dump(struct net *net, struct notifier_block *nb,
534		     struct netlink_ext_ack *extack);
535
536void fib6_update_sernum(struct net *net, struct fib6_info *rt);
537void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
538void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
539
540void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
541static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
542{
543	return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
544}
545void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
546			    bool offload, bool trap, bool offload_failed);
547
548#if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL)
549struct bpf_iter__ipv6_route {
550	__bpf_md_ptr(struct bpf_iter_meta *, meta);
551	__bpf_md_ptr(struct fib6_info *, rt);
552};
553#endif
554
555INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_output(struct net *net,
556					     struct fib6_table *table,
557					     struct flowi6 *fl6,
558					     const struct sk_buff *skb,
559					     int flags));
560INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_input(struct net *net,
561					     struct fib6_table *table,
562					     struct flowi6 *fl6,
563					     const struct sk_buff *skb,
564					     int flags));
565INDIRECT_CALLABLE_DECLARE(struct rt6_info *__ip6_route_redirect(struct net *net,
566					     struct fib6_table *table,
567					     struct flowi6 *fl6,
568					     const struct sk_buff *skb,
569					     int flags));
570INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_lookup(struct net *net,
571					     struct fib6_table *table,
572					     struct flowi6 *fl6,
573					     const struct sk_buff *skb,
574					     int flags));
575static inline struct rt6_info *pol_lookup_func(pol_lookup_t lookup,
576						struct net *net,
577						struct fib6_table *table,
578						struct flowi6 *fl6,
579						const struct sk_buff *skb,
580						int flags)
581{
582	return INDIRECT_CALL_4(lookup,
583			       ip6_pol_route_output,
584			       ip6_pol_route_input,
585			       ip6_pol_route_lookup,
586			       __ip6_route_redirect,
587			       net, table, fl6, skb, flags);
588}
589
590#ifdef CONFIG_IPV6_MULTIPLE_TABLES
591static inline bool fib6_has_custom_rules(const struct net *net)
592{
593	return net->ipv6.fib6_has_custom_rules;
594}
595
596int fib6_rules_init(void);
597void fib6_rules_cleanup(void);
598bool fib6_rule_default(const struct fib_rule *rule);
599int fib6_rules_dump(struct net *net, struct notifier_block *nb,
600		    struct netlink_ext_ack *extack);
601unsigned int fib6_rules_seq_read(struct net *net);
602
603static inline bool fib6_rules_early_flow_dissect(struct net *net,
604						 struct sk_buff *skb,
605						 struct flowi6 *fl6,
606						 struct flow_keys *flkeys)
607{
608	unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
609
610	if (!net->ipv6.fib6_rules_require_fldissect)
611		return false;
612
613	skb_flow_dissect_flow_keys(skb, flkeys, flag);
614	fl6->fl6_sport = flkeys->ports.src;
615	fl6->fl6_dport = flkeys->ports.dst;
616	fl6->flowi6_proto = flkeys->basic.ip_proto;
617
618	return true;
619}
620#else
621static inline bool fib6_has_custom_rules(const struct net *net)
622{
623	return false;
624}
625static inline int               fib6_rules_init(void)
626{
627	return 0;
628}
629static inline void              fib6_rules_cleanup(void)
630{
631	return ;
632}
633static inline bool fib6_rule_default(const struct fib_rule *rule)
634{
635	return true;
636}
637static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
638				  struct netlink_ext_ack *extack)
639{
640	return 0;
641}
642static inline unsigned int fib6_rules_seq_read(struct net *net)
643{
644	return 0;
645}
646static inline bool fib6_rules_early_flow_dissect(struct net *net,
647						 struct sk_buff *skb,
648						 struct flowi6 *fl6,
649						 struct flow_keys *flkeys)
650{
651	return false;
652}
653#endif
654#endif