xref: /linux/include/net/ip_fib.h (revision b72f0db64205d9ce462038ba995d5d31eff32dc1)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET  is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Definitions for the Forwarding Information Base.
8  *
9  * Authors:	A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
10  */
11 
12 #ifndef _NET_IP_FIB_H
13 #define _NET_IP_FIB_H
14 
15 #include <net/flow.h>
16 #include <linux/seq_file.h>
17 #include <linux/rcupdate.h>
18 #include <net/fib_notifier.h>
19 #include <net/fib_rules.h>
20 #include <net/inet_dscp.h>
21 #include <net/inetpeer.h>
22 #include <linux/percpu.h>
23 #include <linux/notifier.h>
24 #include <linux/refcount.h>
25 #include <linux/ip.h>
26 #include <linux/in_route.h>
27 
28 struct fib_config {
29 	u8			fc_dst_len;
30 	dscp_t			fc_dscp;
31 	u8			fc_protocol;
32 	u8			fc_scope;
33 	u8			fc_type;
34 	u8			fc_gw_family;
35 	/* 2 bytes unused */
36 	u32			fc_table;
37 	__be32			fc_dst;
38 	union {
39 		__be32		fc_gw4;
40 		struct in6_addr	fc_gw6;
41 	};
42 	int			fc_oif;
43 	u32			fc_flags;
44 	u32			fc_priority;
45 	__be32			fc_prefsrc;
46 	u32			fc_nh_id;
47 	struct nlattr		*fc_mx;
48 	struct rtnexthop	*fc_mp;
49 	int			fc_mx_len;
50 	int			fc_mp_len;
51 	u32			fc_flow;
52 	u32			fc_nlflags;
53 	struct nl_info		fc_nlinfo;
54 	struct nlattr		*fc_encap;
55 	u16			fc_encap_type;
56 };
57 
58 struct fib_info;
59 struct rtable;
60 
61 struct fib_nh_exception {
62 	struct fib_nh_exception __rcu	*fnhe_next;
63 	int				fnhe_genid;
64 	__be32				fnhe_daddr;
65 	u32				fnhe_pmtu;
66 	bool				fnhe_mtu_locked;
67 	__be32				fnhe_gw;
68 	unsigned long			fnhe_expires;
69 	struct rtable __rcu		*fnhe_rth_input;
70 	struct rtable __rcu		*fnhe_rth_output;
71 	unsigned long			fnhe_stamp;
72 	struct rcu_head			rcu;
73 };
74 
75 struct fnhe_hash_bucket {
76 	struct fib_nh_exception __rcu	*chain;
77 };
78 
79 #define FNHE_HASH_SHIFT		11
80 #define FNHE_HASH_SIZE		(1 << FNHE_HASH_SHIFT)
81 #define FNHE_RECLAIM_DEPTH	5
82 
83 struct fib_nh_common {
84 	struct net_device	*nhc_dev;
85 	netdevice_tracker	nhc_dev_tracker;
86 	int			nhc_oif;
87 	unsigned char		nhc_scope;
88 	u8			nhc_family;
89 	u8			nhc_gw_family;
90 	unsigned char		nhc_flags;
91 	struct lwtunnel_state	*nhc_lwtstate;
92 
93 	union {
94 		__be32          ipv4;
95 		struct in6_addr ipv6;
96 	} nhc_gw;
97 
98 	int			nhc_weight;
99 	atomic_t		nhc_upper_bound;
100 
101 	/* v4 specific, but allows fib6_nh with v4 routes */
102 	struct rtable __rcu * __percpu *nhc_pcpu_rth_output;
103 	struct rtable __rcu     *nhc_rth_input;
104 	struct fnhe_hash_bucket	__rcu *nhc_exceptions;
105 };
106 
107 struct fib_nh {
108 	struct fib_nh_common	nh_common;
109 	struct hlist_node	nh_hash;
110 	struct fib_info		*nh_parent;
111 #ifdef CONFIG_IP_ROUTE_CLASSID
112 	__u32			nh_tclassid;
113 #endif
114 	__be32			nh_saddr;
115 	int			nh_saddr_genid;
116 #define fib_nh_family		nh_common.nhc_family
117 #define fib_nh_dev		nh_common.nhc_dev
118 #define fib_nh_dev_tracker	nh_common.nhc_dev_tracker
119 #define fib_nh_oif		nh_common.nhc_oif
120 #define fib_nh_flags		nh_common.nhc_flags
121 #define fib_nh_lws		nh_common.nhc_lwtstate
122 #define fib_nh_scope		nh_common.nhc_scope
123 #define fib_nh_gw_family	nh_common.nhc_gw_family
124 #define fib_nh_gw4		nh_common.nhc_gw.ipv4
125 #define fib_nh_gw6		nh_common.nhc_gw.ipv6
126 #define fib_nh_weight		nh_common.nhc_weight
127 #define fib_nh_upper_bound	nh_common.nhc_upper_bound
128 };
129 
130 /*
131  * This structure contains data shared by many of routes.
132  */
133 
134 struct nexthop;
135 
136 struct fib_info {
137 	struct hlist_node	fib_hash;
138 	struct hlist_node	fib_lhash;
139 	struct list_head	nh_list;
140 	struct net		*fib_net;
141 	refcount_t		fib_treeref;
142 	refcount_t		fib_clntref;
143 	unsigned int		fib_flags;
144 	unsigned char		fib_dead;
145 	unsigned char		fib_protocol;
146 	unsigned char		fib_scope;
147 	unsigned char		fib_type;
148 	__be32			fib_prefsrc;
149 	u32			fib_tb_id;
150 	u32			fib_priority;
151 	struct dst_metrics	*fib_metrics;
152 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1]
153 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1]
154 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1]
155 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
156 	int			fib_nhs;
157 	bool			fib_nh_is_v6;
158 	bool			nh_updated;
159 	bool			pfsrc_removed;
160 	struct nexthop		*nh;
161 	struct rcu_head		rcu;
162 	struct fib_nh		fib_nh[] __counted_by(fib_nhs);
163 };
164 
165 int __net_init fib4_semantics_init(struct net *net);
166 void __net_exit fib4_semantics_exit(struct net *net);
167 
168 #ifdef CONFIG_IP_MULTIPLE_TABLES
169 struct fib_rule;
170 #endif
171 
172 struct fib_table;
173 struct fib_result {
174 	__be32			prefix;
175 	unsigned char		prefixlen;
176 	unsigned char		nh_sel;
177 	unsigned char		type;
178 	unsigned char		scope;
179 	u32			tclassid;
180 	dscp_t			dscp;
181 	struct fib_nh_common	*nhc;
182 	struct fib_info		*fi;
183 	struct fib_table	*table;
184 	struct hlist_head	*fa_head;
185 };
186 
187 struct fib_result_nl {
188 	__be32		fl_addr;   /* To be looked up*/
189 	u32		fl_mark;
190 	unsigned char	fl_tos;
191 	unsigned char   fl_scope;
192 	unsigned char   tb_id_in;
193 
194 	unsigned char   tb_id;      /* Results */
195 	unsigned char	prefixlen;
196 	unsigned char	nh_sel;
197 	unsigned char	type;
198 	unsigned char	scope;
199 	int             err;
200 };
201 
202 #ifdef CONFIG_IP_MULTIPLE_TABLES
203 #define FIB_TABLE_HASHSZ 256
204 #else
205 #define FIB_TABLE_HASHSZ 2
206 #endif
207 
208 __be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc,
209 				 unsigned char scope);
210 __be32 fib_result_prefsrc(struct net *net, struct fib_result *res);
211 
212 #define FIB_RES_NHC(res)		((res).nhc)
213 #define FIB_RES_DEV(res)	(FIB_RES_NHC(res)->nhc_dev)
214 #define FIB_RES_OIF(res)	(FIB_RES_NHC(res)->nhc_oif)
215 
216 struct fib_rt_info {
217 	struct fib_info		*fi;
218 	u32			tb_id;
219 	__be32			dst;
220 	int			dst_len;
221 	dscp_t			dscp;
222 	u8			type;
223 	u8			offload:1,
224 				trap:1,
225 				offload_failed:1,
226 				unused:5;
227 };
228 
229 struct fib_entry_notifier_info {
230 	struct fib_notifier_info info; /* must be first */
231 	u32 dst;
232 	int dst_len;
233 	struct fib_info *fi;
234 	dscp_t dscp;
235 	u8 type;
236 	u32 tb_id;
237 };
238 
239 struct fib_nh_notifier_info {
240 	struct fib_notifier_info info; /* must be first */
241 	struct fib_nh *fib_nh;
242 };
243 
244 int call_fib4_notifier(struct notifier_block *nb,
245 		       enum fib_event_type event_type,
246 		       struct fib_notifier_info *info);
247 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
248 			struct fib_notifier_info *info);
249 
250 int __net_init fib4_notifier_init(struct net *net);
251 void __net_exit fib4_notifier_exit(struct net *net);
252 
253 void fib_info_notify_update(struct net *net, struct nl_info *info);
254 int fib_notify(struct net *net, struct notifier_block *nb,
255 	       struct netlink_ext_ack *extack);
256 
257 struct fib_table {
258 	struct hlist_node	tb_hlist;
259 	u32			tb_id;
260 	int			tb_num_default;
261 	struct rcu_head		rcu;
262 	unsigned long 		*tb_data;
263 	unsigned long		__data[];
264 };
265 
266 struct fib_dump_filter {
267 	u32			table_id;
268 	/* filter_set is an optimization that an entry is set */
269 	bool			filter_set;
270 	bool			dump_routes;
271 	bool			dump_exceptions;
272 	unsigned char		protocol;
273 	unsigned char		rt_type;
274 	unsigned int		flags;
275 	struct net_device	*dev;
276 };
277 
278 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
279 		     struct fib_result *res, int fib_flags);
280 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
281 		     struct netlink_ext_ack *extack);
282 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
283 		     struct netlink_ext_ack *extack);
284 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
285 		   struct netlink_callback *cb, struct fib_dump_filter *filter);
286 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
287 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
288 void fib_table_flush_external(struct fib_table *table);
289 void fib_free_table(struct fib_table *tb);
290 
291 #ifndef CONFIG_IP_MULTIPLE_TABLES
292 
293 #define TABLE_LOCAL_INDEX	(RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
294 #define TABLE_MAIN_INDEX	(RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))
295 
296 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
297 {
298 	struct hlist_node *tb_hlist;
299 	struct hlist_head *ptr;
300 
301 	ptr = id == RT_TABLE_LOCAL ?
302 		&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
303 		&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
304 
305 	tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
306 
307 	return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
308 }
309 
310 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
311 {
312 	return fib_get_table(net, id);
313 }
314 
315 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
316 			     struct fib_result *res, unsigned int flags)
317 {
318 	struct fib_table *tb;
319 	int err = -ENETUNREACH;
320 
321 	rcu_read_lock();
322 
323 	tb = fib_get_table(net, RT_TABLE_MAIN);
324 	if (tb)
325 		err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
326 
327 	if (err == -EAGAIN)
328 		err = -ENETUNREACH;
329 
330 	rcu_read_unlock();
331 
332 	return err;
333 }
334 
335 static inline bool fib4_has_custom_rules(const struct net *net)
336 {
337 	return false;
338 }
339 
340 static inline bool fib4_rule_default(const struct fib_rule *rule)
341 {
342 	return true;
343 }
344 
345 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb,
346 				  struct netlink_ext_ack *extack)
347 {
348 	return 0;
349 }
350 
351 static inline unsigned int fib4_rules_seq_read(const struct net *net)
352 {
353 	return 0;
354 }
355 
356 static inline bool fib4_rules_early_flow_dissect(struct net *net,
357 						 struct sk_buff *skb,
358 						 struct flowi4 *fl4,
359 						 struct flow_keys *flkeys)
360 {
361 	return false;
362 }
363 #else /* CONFIG_IP_MULTIPLE_TABLES */
364 int __net_init fib4_rules_init(struct net *net);
365 void __net_exit fib4_rules_exit(struct net *net);
366 
367 struct fib_table *fib_new_table(struct net *net, u32 id);
368 struct fib_table *fib_get_table(struct net *net, u32 id);
369 
370 int __fib_lookup(struct net *net, struct flowi4 *flp,
371 		 struct fib_result *res, unsigned int flags);
372 
373 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
374 			     struct fib_result *res, unsigned int flags)
375 {
376 	struct fib_table *tb;
377 	int err = -EAGAIN;
378 
379 	flags |= FIB_LOOKUP_NOREF;
380 	if (net->ipv4.fib_has_custom_rules)
381 		return __fib_lookup(net, flp, res, flags);
382 
383 	rcu_read_lock();
384 
385 	res->tclassid = 0;
386 
387 	tb = rcu_dereference_rtnl(net->ipv4.fib_main);
388 	if (tb)
389 		err = fib_table_lookup(tb, flp, res, flags);
390 
391 	if (err != -EAGAIN)
392 		goto out;
393 
394 	tb = rcu_dereference_rtnl(net->ipv4.fib_default);
395 	if (tb)
396 		err = fib_table_lookup(tb, flp, res, flags);
397 
398 	if (err == -EAGAIN)
399 		err = -ENETUNREACH;
400 out:
401 	rcu_read_unlock();
402 
403 	return err;
404 }
405 
406 static inline bool fib4_has_custom_rules(const struct net *net)
407 {
408 	return net->ipv4.fib_has_custom_rules;
409 }
410 
411 bool fib4_rule_default(const struct fib_rule *rule);
412 int fib4_rules_dump(struct net *net, struct notifier_block *nb,
413 		    struct netlink_ext_ack *extack);
414 unsigned int fib4_rules_seq_read(const struct net *net);
415 
416 static inline bool fib4_rules_early_flow_dissect(struct net *net,
417 						 struct sk_buff *skb,
418 						 struct flowi4 *fl4,
419 						 struct flow_keys *flkeys)
420 {
421 	unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
422 
423 	if (!net->ipv4.fib_rules_require_fldissect)
424 		return false;
425 
426 	memset(flkeys, 0, sizeof(*flkeys));
427 	__skb_flow_dissect(net, skb, &flow_keys_dissector,
428 			   flkeys, NULL, 0, 0, 0, flag);
429 
430 	fl4->fl4_sport = flkeys->ports.src;
431 	fl4->fl4_dport = flkeys->ports.dst;
432 	fl4->flowi4_proto = flkeys->basic.ip_proto;
433 
434 	return true;
435 }
436 
437 #endif /* CONFIG_IP_MULTIPLE_TABLES */
438 
439 static inline bool fib_dscp_masked_match(dscp_t dscp, const struct flowi4 *fl4)
440 {
441 	return dscp == (fl4->flowi4_dscp & INET_DSCP_LEGACY_TOS_MASK);
442 }
443 
444 /* Exported by fib_frontend.c */
445 extern const struct nla_policy rtm_ipv4_policy[];
446 void ip_fib_init(void);
447 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
448 		    struct netlink_ext_ack *extack);
449 __be32 fib_compute_spec_dst(struct sk_buff *skb);
450 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev);
451 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
452 			dscp_t dscp, int oif, struct net_device *dev,
453 			struct in_device *idev, u32 *itag);
454 
455 static inline enum skb_drop_reason
456 fib_validate_source_reason(struct sk_buff *skb, __be32 src, __be32 dst,
457 			   dscp_t dscp, int oif, struct net_device *dev,
458 			   struct in_device *idev, u32 *itag)
459 {
460 	int err = fib_validate_source(skb, src, dst, dscp, oif, dev, idev,
461 				      itag);
462 	if (err < 0)
463 		return -err;
464 	return SKB_NOT_DROPPED_YET;
465 }
466 
467 #ifdef CONFIG_IP_ROUTE_CLASSID
468 static inline int fib_num_tclassid_users(struct net *net)
469 {
470 	return atomic_read(&net->ipv4.fib_num_tclassid_users);
471 }
472 #else
473 static inline int fib_num_tclassid_users(struct net *net)
474 {
475 	return 0;
476 }
477 #endif
478 int fib_unmerge(struct net *net);
479 
480 static inline bool nhc_l3mdev_matches_dev(const struct fib_nh_common *nhc,
481 const struct net_device *dev)
482 {
483 	if (nhc->nhc_dev == dev ||
484 	    l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex)
485 		return true;
486 
487 	return false;
488 }
489 
490 /* Exported by fib_semantics.c */
491 int ip_fib_check_default(__be32 gw, struct net_device *dev);
492 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
493 int fib_sync_down_addr(struct net_device *dev, __be32 local);
494 int fib_sync_up(struct net_device *dev, unsigned char nh_flags);
495 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
496 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig);
497 
498 /* Fields used for sysctl_fib_multipath_hash_fields.
499  * Common to IPv4 and IPv6.
500  *
501  * Add new fields at the end. This is user API.
502  */
503 #define FIB_MULTIPATH_HASH_FIELD_SRC_IP			BIT(0)
504 #define FIB_MULTIPATH_HASH_FIELD_DST_IP			BIT(1)
505 #define FIB_MULTIPATH_HASH_FIELD_IP_PROTO		BIT(2)
506 #define FIB_MULTIPATH_HASH_FIELD_FLOWLABEL		BIT(3)
507 #define FIB_MULTIPATH_HASH_FIELD_SRC_PORT		BIT(4)
508 #define FIB_MULTIPATH_HASH_FIELD_DST_PORT		BIT(5)
509 #define FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP		BIT(6)
510 #define FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP		BIT(7)
511 #define FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO		BIT(8)
512 #define FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL	BIT(9)
513 #define FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT		BIT(10)
514 #define FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT		BIT(11)
515 
516 #define FIB_MULTIPATH_HASH_FIELD_OUTER_MASK		\
517 	(FIB_MULTIPATH_HASH_FIELD_SRC_IP |		\
518 	 FIB_MULTIPATH_HASH_FIELD_DST_IP |		\
519 	 FIB_MULTIPATH_HASH_FIELD_IP_PROTO |		\
520 	 FIB_MULTIPATH_HASH_FIELD_FLOWLABEL |		\
521 	 FIB_MULTIPATH_HASH_FIELD_SRC_PORT |		\
522 	 FIB_MULTIPATH_HASH_FIELD_DST_PORT)
523 
524 #define FIB_MULTIPATH_HASH_FIELD_INNER_MASK		\
525 	(FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP |	\
526 	 FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP |	\
527 	 FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO |	\
528 	 FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL |	\
529 	 FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT |	\
530 	 FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
531 
532 #define FIB_MULTIPATH_HASH_FIELD_ALL_MASK		\
533 	(FIB_MULTIPATH_HASH_FIELD_OUTER_MASK |		\
534 	 FIB_MULTIPATH_HASH_FIELD_INNER_MASK)
535 
536 #define FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK		\
537 	(FIB_MULTIPATH_HASH_FIELD_SRC_IP |		\
538 	 FIB_MULTIPATH_HASH_FIELD_DST_IP |		\
539 	 FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
540 
541 #ifdef CONFIG_IP_ROUTE_MULTIPATH
542 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
543 		       const struct sk_buff *skb, struct flow_keys *flkeys);
544 
545 static void
546 fib_multipath_hash_construct_key(siphash_key_t *key, u32 mp_seed)
547 {
548 	u64 mp_seed_64 = mp_seed;
549 
550 	key->key[0] = (mp_seed_64 << 32) | mp_seed_64;
551 	key->key[1] = key->key[0];
552 }
553 
554 static inline u32 fib_multipath_hash_from_keys(const struct net *net,
555 					       struct flow_keys *keys)
556 {
557 	siphash_aligned_key_t hash_key;
558 	u32 mp_seed;
559 
560 	mp_seed = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed.mp_seed);
561 	fib_multipath_hash_construct_key(&hash_key, mp_seed);
562 
563 	return flow_hash_from_keys_seed(keys, &hash_key);
564 }
565 #else
566 static inline u32 fib_multipath_hash_from_keys(const struct net *net,
567 					       struct flow_keys *keys)
568 {
569 	return flow_hash_from_keys(keys);
570 }
571 #endif
572 
573 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
574 		 struct netlink_ext_ack *extack);
575 void fib_select_multipath(struct fib_result *res, int hash,
576 			  const struct flowi4 *fl4);
577 void fib_select_path(struct net *net, struct fib_result *res,
578 		     struct flowi4 *fl4, const struct sk_buff *skb);
579 
580 int fib_nh_init(struct net *net, struct fib_nh *fib_nh,
581 		struct fib_config *cfg, int nh_weight,
582 		struct netlink_ext_ack *extack);
583 void fib_nh_release(struct net *net, struct fib_nh *fib_nh);
584 int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc,
585 		       struct nlattr *fc_encap, u16 fc_encap_type,
586 		       void *cfg, gfp_t gfp_flags,
587 		       struct netlink_ext_ack *extack);
588 void fib_nh_common_release(struct fib_nh_common *nhc);
589 
590 /* Exported by fib_trie.c */
591 void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri);
592 void fib_trie_init(void);
593 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
594 bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags,
595 			 const struct flowi4 *flp);
596 
597 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
598 {
599 #ifdef CONFIG_IP_ROUTE_CLASSID
600 	struct fib_nh_common *nhc = res->nhc;
601 #ifdef CONFIG_IP_MULTIPLE_TABLES
602 	u32 rtag;
603 #endif
604 	if (nhc->nhc_family == AF_INET) {
605 		struct fib_nh *nh;
606 
607 		nh = container_of(nhc, struct fib_nh, nh_common);
608 		*itag = nh->nh_tclassid << 16;
609 	} else {
610 		*itag = 0;
611 	}
612 
613 #ifdef CONFIG_IP_MULTIPLE_TABLES
614 	rtag = res->tclassid;
615 	if (*itag == 0)
616 		*itag = (rtag<<16);
617 	*itag |= (rtag>>16);
618 #endif
619 #endif
620 }
621 
622 void fib_flush(struct net *net);
623 void free_fib_info(struct fib_info *fi);
624 
625 static inline void fib_info_hold(struct fib_info *fi)
626 {
627 	refcount_inc(&fi->fib_clntref);
628 }
629 
630 static inline bool fib_info_hold_safe(struct fib_info *fi)
631 {
632 	return refcount_inc_not_zero(&fi->fib_clntref);
633 }
634 
635 static inline void fib_info_put(struct fib_info *fi)
636 {
637 	if (refcount_dec_and_test(&fi->fib_clntref))
638 		free_fib_info(fi);
639 }
640 
641 #ifdef CONFIG_PROC_FS
642 int __net_init fib_proc_init(struct net *net);
643 void __net_exit fib_proc_exit(struct net *net);
644 #else
645 static inline int fib_proc_init(struct net *net)
646 {
647 	return 0;
648 }
649 static inline void fib_proc_exit(struct net *net)
650 {
651 }
652 #endif
653 
654 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);
655 
656 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
657 			  struct fib_dump_filter *filter,
658 			  struct netlink_callback *cb);
659 
660 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh,
661 		     u8 rt_family, unsigned char *flags, bool skip_oif);
662 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh,
663 		    int nh_weight, u8 rt_family, u32 nh_tclassid);
664 #endif  /* _NET_FIB_H */
665