summaryrefslogtreecommitdiffstats
path: root/include/net/ip_fib.h
blob: b219a8fe0950b99a88d057816dcf1b7cb48080a8 (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
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET  is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Definitions for the Forwarding Information Base.
 *
 * Authors:	A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
 */

#ifndef _NET_IP_FIB_H
#define _NET_IP_FIB_H

#include <net/flow.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
#include <net/fib_notifier.h>
#include <net/fib_rules.h>
#include <net/inetpeer.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/refcount.h>

struct fib_config {
	u8			fc_dst_len;
	u8			fc_tos;
	u8			fc_protocol;
	u8			fc_scope;
	u8			fc_type;
	u8			fc_gw_family;
	/* 2 bytes unused */
	u32			fc_table;
	__be32			fc_dst;
	union {
		__be32		fc_gw4;
		struct in6_addr	fc_gw6;
	};
	int			fc_oif;
	u32			fc_flags;
	u32			fc_priority;
	__be32			fc_prefsrc;
	u32			fc_nh_id;
	struct nlattr		*fc_mx;
	struct rtnexthop	*fc_mp;
	int			fc_mx_len;
	int			fc_mp_len;
	u32			fc_flow;
	u32			fc_nlflags;
	struct nl_info		fc_nlinfo;
	struct nlattr		*fc_encap;
	u16			fc_encap_type;
};

struct fib_info;
struct rtable;

struct fib_nh_exception {
	struct fib_nh_exception __rcu	*fnhe_next;
	int				fnhe_genid;
	__be32				fnhe_daddr;
	u32				fnhe_pmtu;
	bool				fnhe_mtu_locked;
	__be32				fnhe_gw;
	unsigned long			fnhe_expires;
	struct rtable __rcu		*fnhe_rth_input;
	struct rtable __rcu		*fnhe_rth_output;
	unsigned long			fnhe_stamp;
	struct rcu_head			rcu;
};

struct fnhe_hash_bucket {
	struct fib_nh_exception __rcu	*chain;
};

#define FNHE_HASH_SHIFT		11
#define FNHE_HASH_SIZE		(1 << FNHE_HASH_SHIFT)
#define FNHE_RECLAIM_DEPTH	5

struct fib_nh_common {
	struct net_device	*nhc_dev;
	int			nhc_oif;
	unsigned char		nhc_scope;
	u8			nhc_family;
	u8			nhc_gw_family;
	unsigned char		nhc_flags;
	struct lwtunnel_state	*nhc_lwtstate;

	union {
		__be32          ipv4;
		struct in6_addr ipv6;
	} nhc_gw;

	int			nhc_weight;
	atomic_t		nhc_upper_bound;

	/* v4 specific, but allows fib6_nh with v4 routes */
	struct rtable __rcu * __percpu *nhc_pcpu_rth_output;
	struct rtable __rcu     *nhc_rth_input;
	struct fnhe_hash_bucket	__rcu *nhc_exceptions;
};

struct fib_nh {
	struct fib_nh_common	nh_common;
	struct hlist_node	nh_hash;
	struct fib_info		*nh_parent;
#ifdef CONFIG_IP_ROUTE_CLASSID
	__u32			nh_tclassid;
#endif
	__be32			nh_saddr;
	int			nh_saddr_genid;
#define fib_nh_family		nh_common.nhc_family
#define fib_nh_dev		nh_common.nhc_dev
#define fib_nh_oif		nh_common.nhc_oif
#define fib_nh_flags		nh_common.nhc_flags
#define fib_nh_lws		nh_common.nhc_lwtstate
#define fib_nh_scope		nh_common.nhc_scope
#define fib_nh_gw_family	nh_common.nhc_gw_family
#define fib_nh_gw4		nh_common.nhc_gw.ipv4
#define fib_nh_gw6		nh_common.nhc_gw.ipv6
#define fib_nh_weight		nh_common.nhc_weight
#define fib_nh_upper_bound	nh_common.nhc_upper_bound
};

/*
 * This structure contains data shared by many of routes.
 */

struct nexthop;

struct fib_info {
	struct hlist_node	fib_hash;
	struct hlist_node	fib_lhash;
	struct list_head	nh_list;
	struct net		*fib_net;
	int			fib_treeref;
	refcount_t		fib_clntref;
	unsigned int		fib_flags;
	unsigned char		fib_dead;
	unsigned char		fib_protocol;
	unsigned char		fib_scope;
	unsigned char		fib_type;
	__be32			fib_prefsrc;
	u32			fib_tb_id;
	u32			fib_priority;
	struct dst_metrics	*fib_metrics;
#define fib_mtu fib_metrics->metrics[RTAX_MTU-1]
#define fib_window fib_metrics->metrics[RTAX_WINDOW-1]
#define fib_rtt fib_metrics->metrics[RTAX_RTT-1]
#define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
	int			fib_nhs;
	bool			fib_nh_is_v6;
	bool			nh_updated;
	struct nexthop		*nh;
	struct rcu_head		rcu;
	struct fib_nh		fib_nh[];
};


#ifdef CONFIG_IP_MULTIPLE_TABLES
struct fib_rule;
#endif

struct fib_table;
struct fib_result {
	__be32			prefix;
	unsigned char		prefixlen;
	unsigned char		nh_sel;
	unsigned char		type;
	unsigned char		scope;
	u32			tclassid;
	struct fib_nh_common	*nhc;
	struct fib_info		*fi;
	struct fib_table	*table;
	struct hlist_head	*fa_head;
};

struct fib_result_nl {
	__be32		fl_addr;   /* To be looked up*/
	u32		fl_mark;
	unsigned char	fl_tos;
	unsigned char   fl_scope;
	unsigned char   tb_id_in;

	unsigned char   tb_id;      /* Results */
	unsigned char	prefixlen;
	unsigned char	nh_sel;
	unsigned char	type;
	unsigned char	scope;
	int             err;
};

#ifdef CONFIG_IP_MULTIPLE_TABLES
#define FIB_TABLE_HASHSZ 256
#else
#define FIB_TABLE_HASHSZ 2
#endif

__be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc,
				 unsigned char scope);
__be32 fib_result_prefsrc(struct net *net, struct fib_result *res);

#define FIB_RES_NHC(res)		((res).nhc)
#define FIB_RES_DEV(res)	(FIB_RES_NHC(res)->nhc_dev)
#define FIB_RES_OIF(res)	(FIB_RES_NHC(res)->nhc_oif)

struct fib_rt_info {
	struct fib_info		*fi;
	u32			tb_id;
	__be32			dst;
	int			dst_len;
	u8			tos;
	u8			type;
	u8			offload:1,
				trap:1,
				unused:6;
};

struct fib_entry_notifier_info {
	struct fib_notifier_info info; /* must be first */
	u32 dst;
	int dst_len;
	struct fib_info *fi;
	u8 tos;
	u8 type;
	u32 tb_id;
};

struct fib_nh_notifier_info {
	struct fib_notifier_info info; /* must be first */
	struct fib_nh *fib_nh;
};

int call_fib4_notifier(struct notifier_block *nb,
		       enum fib_event_type event_type,
		       struct fib_notifier_info *info);
int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
			struct fib_notifier_info *info);

int __net_init fib4_notifier_init(struct net *net);
void __net_exit fib4_notifier_exit(struct net *net);

void fib_info_notify_update(struct net *net, struct nl_info *info);
int fib_notify(struct net *net, struct notifier_block *nb,
	       struct netlink_ext_ack *extack);

struct fib_table {
	struct hlist_node	tb_hlist;
	u32			tb_id;
	int			tb_num_default;
	struct rcu_head		rcu;
	unsigned long 		*tb_data;
	unsigned long		__data[];
};

struct fib_dump_filter {
	u32			table_id;
	/* filter_set is an optimization that an entry is set */
	bool			filter_set;
	bool			dump_routes;
	bool			dump_exceptions;
	unsigned char		protocol;
	unsigned char		rt_type;
	unsigned int		flags;
	struct net_device	*dev;
};

int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
		     struct fib_result *res, int fib_flags);
int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
		     struct netlink_ext_ack *extack);
int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
		     struct netlink_ext_ack *extack);
int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
		   struct netlink_callback *cb, struct fib_dump_filter *filter);
int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
void fib_table_flush_external(struct fib_table *table);
void fib_free_table(struct fib_table *tb);

#ifndef CONFIG_IP_MULTIPLE_TABLES

#define TABLE_LOCAL_INDEX	(RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
#define TABLE_MAIN_INDEX	(RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))

static inline struct fib_table *fib_get_table(struct net *net, u32 id)
{
	struct hlist_node *tb_hlist;
	struct hlist_head *ptr;

	ptr = id == RT_TABLE_LOCAL ?
		&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
		&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];

	tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));

	return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
}

static inline struct fib_table *fib_new_table(struct net *net, u32 id)
{
	return fib_get_table(net, id);
}

static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
			     struct fib_result *res, unsigned int flags)
{
	struct fib_table *tb;
	int err = -ENETUNREACH;

	rcu_read_lock();

	tb = fib_get_table(net, RT_TABLE_MAIN);
	if (tb)
		err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);

	if (err == -EAGAIN)
		err = -ENETUNREACH;

	rcu_read_unlock();

	return err;
}

static inline bool fib4_has_custom_rules(const struct net *net)
{
	return false;
}

static inline bool fib4_rule_default(const struct fib_rule *rule)
{
	return true;
}

static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb,
				  struct netlink_ext_ack *extack)
{
	return 0;
}

static inline unsigned int fib4_rules_seq_read(struct net *net)
{
	return 0;
}

static inline bool fib4_rules_early_flow_dissect(struct net *net,
						 struct sk_buff *skb,
						 struct flowi4 *fl4,
						 struct flow_keys *flkeys)
{
	return false;
}
#else /* CONFIG_IP_MULTIPLE_TABLES */
int __net_init fib4_rules_init(struct net *net);
void __net_exit fib4_rules_exit(struct net *net);

struct fib_table *fib_new_table(struct net *net, u32 id);
struct fib_table *fib_get_table(struct net *net, u32 id);

int __fib_lookup(struct net *net, struct flowi4 *flp,
		 struct fib_result *res, unsigned int flags);

static inline int fib_lookup(struct net *net, struct flowi4 *flp,
			     struct fib_result *res, unsigned int flags)
{
	struct fib_table *tb;
	int err = -ENETUNREACH;

	flags |= FIB_LOOKUP_NOREF;
	if (net->ipv4.fib_has_custom_rules)
		return __fib_lookup(net, flp, res, flags);

	rcu_read_lock();

	res->tclassid = 0;

	tb = rcu_dereference_rtnl(net->ipv4.fib_main);
	if (tb)
		err = fib_table_lookup(tb, flp, res, flags);

	if (!err)
		goto out;

	tb = rcu_dereference_rtnl(net->ipv4.fib_default);
	if (tb)
		err = fib_table_lookup(tb, flp, res, flags);

out:
	if (err == -EAGAIN)
		err = -ENETUNREACH;

	rcu_read_unlock();

	return err;
}

static inline bool fib4_has_custom_rules(const struct net *net)
{
	return net->ipv4.fib_has_custom_rules;
}

bool fib4_rule_default(const struct fib_rule *rule);
int fib4_rules_dump(struct net *net, struct notifier_block *nb,
		    struct netlink_ext_ack *extack);
unsigned int fib4_rules_seq_read(struct net *net);

static inline bool fib4_rules_early_flow_dissect(struct net *net,
						 struct sk_buff *skb,
						 struct flowi4 *fl4,
						 struct flow_keys *flkeys)
{
	unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;

	if (!net->ipv4.fib_rules_require_fldissect)
		return false;

	skb_flow_dissect_flow_keys(skb, flkeys, flag);
	fl4->fl4_sport = flkeys->ports.src;
	fl4->fl4_dport = flkeys->ports.dst;
	fl4->flowi4_proto = flkeys->basic.ip_proto;

	return true;
}

#endif /* CONFIG_IP_MULTIPLE_TABLES */

/* Exported by fib_frontend.c */
extern const struct nla_policy rtm_ipv4_policy[];
void ip_fib_init(void);
int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
		    struct netlink_ext_ack *extack);
__be32 fib_compute_spec_dst(struct sk_buff *skb);
bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev);
int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
			u8 tos, int oif, struct net_device *dev,
			struct in_device *idev, u32 *itag);
#ifdef CONFIG_IP_ROUTE_CLASSID
static inline int fib_num_tclassid_users(struct net *net)
{
	return net->ipv4.fib_num_tclassid_users;
}
#else
static inline int fib_num_tclassid_users(struct net *net)
{
	return 0;
}
#endif
int fib_unmerge(struct net *net);

/* Exported by fib_semantics.c */
int ip_fib_check_default(__be32 gw, struct net_device *dev);
int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
int fib_sync_down_addr(struct net_device *dev, __be32 local);
int fib_sync_up(struct net_device *dev, unsigned char nh_flags);
void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig);

#ifdef CONFIG_IP_ROUTE_MULTIPATH
int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
		       const struct sk_buff *skb, struct flow_keys *flkeys);
#endif
int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
		 struct netlink_ext_ack *extack);
void fib_select_multipath(struct fib_result *res, int hash);
void fib_select_path(struct net *net, struct fib_result *res,
		     struct flowi4 *fl4, const struct sk_buff *skb);

int fib_nh_init(struct net *net, struct fib_nh *fib_nh,
		struct fib_config *cfg, int nh_weight,
		struct netlink_ext_ack *extack);
void fib_nh_release(struct net *net, struct fib_nh *fib_nh);
int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc,
		       struct nlattr *fc_encap, u16 fc_encap_type,
		       void *cfg, gfp_t gfp_flags,
		       struct netlink_ext_ack *extack);
void fib_nh_common_release(struct fib_nh_common *nhc);

/* Exported by fib_trie.c */
void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri);
void fib_trie_init(void);
struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);

static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
{
#ifdef CONFIG_IP_ROUTE_CLASSID
	struct fib_nh_common *nhc = res->nhc;
#ifdef CONFIG_IP_MULTIPLE_TABLES
	u32 rtag;
#endif
	if (nhc->nhc_family == AF_INET) {
		struct fib_nh *nh;

		nh = container_of(nhc, struct fib_nh, nh_common);
		*itag = nh->nh_tclassid << 16;
	} else {
		*itag = 0;
	}

#ifdef CONFIG_IP_MULTIPLE_TABLES
	rtag = res->tclassid;
	if (*itag == 0)
		*itag = (rtag<<16);
	*itag |= (rtag>>16);
#endif
#endif
}

void fib_flush(struct net *net);
void free_fib_info(struct fib_info *fi);

static inline void fib_info_hold(struct fib_info *fi)
{
	refcount_inc(&fi->fib_clntref);
}

static inline void fib_info_put(struct fib_info *fi)
{
	if (refcount_dec_and_test(&fi->fib_clntref))
		free_fib_info(fi);
}

#ifdef CONFIG_PROC_FS
int __net_init fib_proc_init(struct net *net);
void __net_exit fib_proc_exit(struct net *net);
#else
static inline int fib_proc_init(struct net *net)
{
	return 0;
}
static inline void fib_proc_exit(struct net *net)
{
}
#endif

u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);

int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
			  struct fib_dump_filter *filter,
			  struct netlink_callback *cb);

int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh,
		     u8 rt_family, unsigned char *flags, bool skip_oif);
int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh,
		    int nh_weight, u8 rt_family);
#endif  /* _NET_FIB_H */