summaryrefslogtreecommitdiff
path: root/include/net/ip6_fib.h
blob: 34ec321d6a03baaf1efdfe591a5ca1f27b1d276c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
/*
 *	Linux INET6 implementation 
 *
 *	Authors:
 *	Pedro Roque		<roque@di.fc.ul.pt>	
 *
 *	This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#ifndef _IP6_FIB_H
#define _IP6_FIB_H

#include <linux/ipv6_route.h>
#include <linux/rtnetlink.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/netlink.h>
#include <net/inetpeer.h>
#include <net/fib_notifier.h>

#ifdef CONFIG_IPV6_MULTIPLE_TABLES
#define FIB6_TABLE_HASHSZ 256
#else
#define FIB6_TABLE_HASHSZ 1
#endif

#define RT6_DEBUG 2

#if RT6_DEBUG >= 3
#define RT6_TRACE(x...) pr_debug(x)
#else
#define RT6_TRACE(x...) do { ; } while (0)
#endif

struct rt6_info;

struct fib6_config {
	u32		fc_table;
	u32		fc_metric;
	int		fc_dst_len;
	int		fc_src_len;
	int		fc_ifindex;
	u32		fc_flags;
	u32		fc_protocol;
	u16		fc_type;        /* only 8 bits are used */
	u16		fc_delete_all_nh : 1,
			__unused : 15;

	struct in6_addr	fc_dst;
	struct in6_addr	fc_src;
	struct in6_addr	fc_prefsrc;
	struct in6_addr	fc_gateway;

	unsigned long	fc_expires;
	struct nlattr	*fc_mx;
	int		fc_mx_len;
	int		fc_mp_len;
	struct nlattr	*fc_mp;

	struct nl_info	fc_nlinfo;
	struct nlattr	*fc_encap;
	u16		fc_encap_type;
};

struct fib6_node {
	struct fib6_node __rcu	*parent;
	struct fib6_node __rcu	*left;
	struct fib6_node __rcu	*right;
#ifdef CONFIG_IPV6_SUBTREES
	struct fib6_node __rcu	*subtree;
#endif
	struct rt6_info __rcu	*leaf;

	__u16			fn_bit;		/* bit key */
	__u16			fn_flags;
	int			fn_sernum;
	struct rt6_info __rcu	*rr_ptr;
	struct rcu_head		rcu;
};

struct fib6_gc_args {
	int			timeout;
	int			more;
};

#ifndef CONFIG_IPV6_SUBTREES
#define FIB6_SUBTREE(fn)	NULL
#else
#define FIB6_SUBTREE(fn)	(rcu_dereference_protected((fn)->subtree, 1))
#endif

struct mx6_config {
	const u32 *mx;
	DECLARE_BITMAP(mx_valid, RTAX_MAX);
};

/*
 *	routing information
 *
 */

struct rt6key {
	struct in6_addr	addr;
	int		plen;
};

struct fib6_table;

struct rt6_exception_bucket {
	struct hlist_head	chain;
	int			depth;
};

struct rt6_exception {
	struct hlist_node	hlist;
	struct rt6_info		*rt6i;
	unsigned long		stamp;
	struct rcu_head		rcu;
};

#define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
#define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
#define FIB6_MAX_DEPTH 5

struct rt6_info {
	struct dst_entry		dst;
	struct rt6_info __rcu		*rt6_next;
	struct rt6_info			*from;

	/*
	 * Tail elements of dst_entry (__refcnt etc.)
	 * and these elements (rarely used in hot path) are in
	 * the same cache line.
	 */
	struct fib6_table		*rt6i_table;
	struct fib6_node __rcu		*rt6i_node;

	struct in6_addr			rt6i_gateway;

	/* Multipath routes:
	 * siblings is a list of rt6_info that have the the same metric/weight,
	 * destination, but not the same gateway. nsiblings is just a cache
	 * to speed up lookup.
	 */
	struct list_head		rt6i_siblings;
	unsigned int			rt6i_nsiblings;
	atomic_t			rt6i_nh_upper_bound;

	atomic_t			rt6i_ref;

	unsigned int			rt6i_nh_flags;

	/* These are in a separate cache line. */
	struct rt6key			rt6i_dst ____cacheline_aligned_in_smp;
	u32				rt6i_flags;
	struct rt6key			rt6i_src;
	struct rt6key			rt6i_prefsrc;

	struct list_head		rt6i_uncached;
	struct uncached_list		*rt6i_uncached_list;

	struct inet6_dev		*rt6i_idev;
	struct rt6_info * __percpu	*rt6i_pcpu;
	struct rt6_exception_bucket __rcu *rt6i_exception_bucket;

	u32				rt6i_metric;
	u32				rt6i_pmtu;
	/* more non-fragment space at head required */
	int				rt6i_nh_weight;
	unsigned short			rt6i_nfheader_len;
	u8				rt6i_protocol;
	u8				exception_bucket_flushed:1,
					should_flush:1,
					unused:6;
};

#define for_each_fib6_node_rt_rcu(fn)					\
	for (rt = rcu_dereference((fn)->leaf); rt;			\
	     rt = rcu_dereference(rt->rt6_next))

#define for_each_fib6_walker_rt(w)					\
	for (rt = (w)->leaf; rt;					\
	     rt = rcu_dereference_protected(rt->rt6_next, 1))

static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
{
	return ((struct rt6_info *)dst)->rt6i_idev;
}

static inline void rt6_clean_expires(struct rt6_info *rt)
{
	rt->rt6i_flags &= ~RTF_EXPIRES;
	rt->dst.expires = 0;
}

static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
{
	rt->dst.expires = expires;
	rt->rt6i_flags |= RTF_EXPIRES;
}

static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
{
	struct rt6_info *rt;

	for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES); rt = rt->from);
	if (rt && rt != rt0)
		rt0->dst.expires = rt->dst.expires;
	dst_set_expires(&rt0->dst, timeout);
	rt0->rt6i_flags |= RTF_EXPIRES;
}

/* Function to safely get fn->sernum for passed in rt
 * and store result in passed in cookie.
 * Return true if we can get cookie safely
 * Return false if not
 */
static inline bool rt6_get_cookie_safe(const struct rt6_info *rt,
				       u32 *cookie)
{
	struct fib6_node *fn;
	bool status = false;

	rcu_read_lock();
	fn = rcu_dereference(rt->rt6i_node);

	if (fn) {
		*cookie = fn->fn_sernum;
		/* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
		smp_rmb();
		status = true;
	}

	rcu_read_unlock();
	return status;
}

static inline u32 rt6_get_cookie(const struct rt6_info *rt)
{
	u32 cookie = 0;

	if (rt->rt6i_flags & RTF_PCPU ||
	    (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->from))
		rt = rt->from;

	rt6_get_cookie_safe(rt, &cookie);

	return cookie;
}

static inline void ip6_rt_put(struct rt6_info *rt)
{
	/* dst_release() accepts a NULL parameter.
	 * We rely on dst being first structure in struct rt6_info
	 */
	BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
	dst_release(&rt->dst);
}

void rt6_free_pcpu(struct rt6_info *non_pcpu_rt);

static inline void rt6_hold(struct rt6_info *rt)
{
	atomic_inc(&rt->rt6i_ref);
}

static inline void rt6_release(struct rt6_info *rt)
{
	if (atomic_dec_and_test(&rt->rt6i_ref)) {
		rt6_free_pcpu(rt);
		dst_dev_put(&rt->dst);
		dst_release(&rt->dst);
	}
}

enum fib6_walk_state {
#ifdef CONFIG_IPV6_SUBTREES
	FWS_S,
#endif
	FWS_L,
	FWS_R,
	FWS_C,
	FWS_U
};

struct fib6_walker {
	struct list_head lh;
	struct fib6_node *root, *node;
	struct rt6_info *leaf;
	enum fib6_walk_state state;
	unsigned int skip;
	unsigned int count;
	int (*func)(struct fib6_walker *);
	void *args;
};

struct rt6_statistics {
	__u32		fib_nodes;		/* all fib6 nodes */
	__u32		fib_route_nodes;	/* intermediate nodes */
	__u32		fib_rt_entries;		/* rt entries in fib table */
	__u32		fib_rt_cache;		/* cached rt entries in exception table */
	__u32		fib_discarded_routes;	/* total number of routes delete */

	/* The following stats are not protected by any lock */
	atomic_t	fib_rt_alloc;		/* total number of routes alloced */
	atomic_t	fib_rt_uncache;		/* rt entries in uncached list */
};

#define RTN_TL_ROOT	0x0001
#define RTN_ROOT	0x0002		/* tree root node		*/
#define RTN_RTINFO	0x0004		/* node with valid routing info	*/

/*
 *	priority levels (or metrics)
 *
 */


struct fib6_table {
	struct hlist_node	tb6_hlist;
	u32			tb6_id;
	spinlock_t		tb6_lock;
	struct fib6_node	tb6_root;
	struct inet_peer_base	tb6_peers;
	unsigned int		flags;
	unsigned int		fib_seq;
#define RT6_TABLE_HAS_DFLT_ROUTER	BIT(0)
};

#define RT6_TABLE_UNSPEC	RT_TABLE_UNSPEC
#define RT6_TABLE_MAIN		RT_TABLE_MAIN
#define RT6_TABLE_DFLT		RT6_TABLE_MAIN
#define RT6_TABLE_INFO		RT6_TABLE_MAIN
#define RT6_TABLE_PREFIX	RT6_TABLE_MAIN

#ifdef CONFIG_IPV6_MULTIPLE_TABLES
#define FIB6_TABLE_MIN		1
#define FIB6_TABLE_MAX		RT_TABLE_MAX
#define RT6_TABLE_LOCAL		RT_TABLE_LOCAL
#else
#define FIB6_TABLE_MIN		RT_TABLE_MAIN
#define FIB6_TABLE_MAX		FIB6_TABLE_MIN
#define RT6_TABLE_LOCAL		RT6_TABLE_MAIN
#endif

typedef struct rt6_info *(*pol_lookup_t)(struct net *,
					 struct fib6_table *,
					 struct flowi6 *, int);

struct fib6_entry_notifier_info {
	struct fib_notifier_info info; /* must be first */
	struct rt6_info *rt;
};

/*
 *	exported functions
 */

struct fib6_table *fib6_get_table(struct net *net, u32 id);
struct fib6_table *fib6_new_table(struct net *net, u32 id);
struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
				   int flags, pol_lookup_t lookup);

struct fib6_node *fib6_lookup(struct fib6_node *root,
			      const struct in6_addr *daddr,
			      const struct in6_addr *saddr);

struct fib6_node *fib6_locate(struct fib6_node *root,
			      const struct in6_addr *daddr, int dst_len,
			      const struct in6_addr *saddr, int src_len,
			      bool exact_match);

void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
		    void *arg);

int fib6_add(struct fib6_node *root, struct rt6_info *rt,
	     struct nl_info *info, struct mx6_config *mxc,
	     struct netlink_ext_ack *extack);
int fib6_del(struct rt6_info *rt, struct nl_info *info);

void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info,
		     unsigned int flags);

void fib6_run_gc(unsigned long expires, struct net *net, bool force);

void fib6_gc_cleanup(void);

int fib6_init(void);

int ipv6_route_open(struct inode *inode, struct file *file);

int call_fib6_notifier(struct notifier_block *nb, struct net *net,
		       enum fib_event_type event_type,
		       struct fib_notifier_info *info);
int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
			struct fib_notifier_info *info);

int __net_init fib6_notifier_init(struct net *net);
void __net_exit fib6_notifier_exit(struct net *net);

unsigned int fib6_tables_seq_read(struct net *net);
int fib6_tables_dump(struct net *net, struct notifier_block *nb);

void fib6_update_sernum(struct rt6_info *rt);
void fib6_update_sernum_upto_root(struct net *net, struct rt6_info *rt);

#ifdef CONFIG_IPV6_MULTIPLE_TABLES
int fib6_rules_init(void);
void fib6_rules_cleanup(void);
bool fib6_rule_default(const struct fib_rule *rule);
int fib6_rules_dump(struct net *net, struct notifier_block *nb);
unsigned int fib6_rules_seq_read(struct net *net);
#else
static inline int               fib6_rules_init(void)
{
	return 0;
}
static inline void              fib6_rules_cleanup(void)
{
	return ;
}
static inline bool fib6_rule_default(const struct fib_rule *rule)
{
	return true;
}
static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb)
{
	return 0;
}
static inline unsigned int fib6_rules_seq_read(struct net *net)
{
	return 0;
}
#endif
#endif