xref: /linux/include/net/ip_fib.h (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 
166 #ifdef CONFIG_IP_MULTIPLE_TABLES
167 struct fib_rule;
168 #endif
169 
170 struct fib_table;
171 struct fib_result {
172 	__be32			prefix;
173 	unsigned char		prefixlen;
174 	unsigned char		nh_sel;
175 	unsigned char		type;
176 	unsigned char		scope;
177 	u32			tclassid;
178 	dscp_t			dscp;
179 	struct fib_nh_common	*nhc;
180 	struct fib_info		*fi;
181 	struct fib_table	*table;
182 	struct hlist_head	*fa_head;
183 };
184 
185 struct fib_result_nl {
186 	__be32		fl_addr;   /* To be looked up*/
187 	u32		fl_mark;
188 	unsigned char	fl_tos;
189 	unsigned char   fl_scope;
190 	unsigned char   tb_id_in;
191 
192 	unsigned char   tb_id;      /* Results */
193 	unsigned char	prefixlen;
194 	unsigned char	nh_sel;
195 	unsigned char	type;
196 	unsigned char	scope;
197 	int             err;
198 };
199 
200 #ifdef CONFIG_IP_MULTIPLE_TABLES
201 #define FIB_TABLE_HASHSZ 256
202 #else
203 #define FIB_TABLE_HASHSZ 2
204 #endif
205 
206 __be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc,
207 				 unsigned char scope);
208 __be32 fib_result_prefsrc(struct net *net, struct fib_result *res);
209 
210 #define FIB_RES_NHC(res)		((res).nhc)
211 #define FIB_RES_DEV(res)	(FIB_RES_NHC(res)->nhc_dev)
212 #define FIB_RES_OIF(res)	(FIB_RES_NHC(res)->nhc_oif)
213 
214 struct fib_rt_info {
215 	struct fib_info		*fi;
216 	u32			tb_id;
217 	__be32			dst;
218 	int			dst_len;
219 	dscp_t			dscp;
220 	u8			type;
221 	u8			offload:1,
222 				trap:1,
223 				offload_failed:1,
224 				unused:5;
225 };
226 
227 struct fib_entry_notifier_info {
228 	struct fib_notifier_info info; /* must be first */
229 	u32 dst;
230 	int dst_len;
231 	struct fib_info *fi;
232 	dscp_t dscp;
233 	u8 type;
234 	u32 tb_id;
235 };
236 
237 struct fib_nh_notifier_info {
238 	struct fib_notifier_info info; /* must be first */
239 	struct fib_nh *fib_nh;
240 };
241 
242 int call_fib4_notifier(struct notifier_block *nb,
243 		       enum fib_event_type event_type,
244 		       struct fib_notifier_info *info);
245 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
246 			struct fib_notifier_info *info);
247 
248 int __net_init fib4_notifier_init(struct net *net);
249 void __net_exit fib4_notifier_exit(struct net *net);
250 
251 void fib_info_notify_update(struct net *net, struct nl_info *info);
252 int fib_notify(struct net *net, struct notifier_block *nb,
253 	       struct netlink_ext_ack *extack);
254 
255 struct fib_table {
256 	struct hlist_node	tb_hlist;
257 	u32			tb_id;
258 	int			tb_num_default;
259 	struct rcu_head		rcu;
260 	unsigned long 		*tb_data;
261 	unsigned long		__data[];
262 };
263 
264 struct fib_dump_filter {
265 	u32			table_id;
266 	/* filter_set is an optimization that an entry is set */
267 	bool			filter_set;
268 	bool			dump_routes;
269 	bool			dump_exceptions;
270 	bool			rtnl_held;
271 	unsigned char		protocol;
272 	unsigned char		rt_type;
273 	unsigned int		flags;
274 	struct net_device	*dev;
275 };
276 
277 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
278 		     struct fib_result *res, int fib_flags);
279 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
280 		     struct netlink_ext_ack *extack);
281 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
282 		     struct netlink_ext_ack *extack);
283 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
284 		   struct netlink_callback *cb, struct fib_dump_filter *filter);
285 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
286 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
287 void fib_table_flush_external(struct fib_table *table);
288 void fib_free_table(struct fib_table *tb);
289 
290 #ifndef CONFIG_IP_MULTIPLE_TABLES
291 
292 #define TABLE_LOCAL_INDEX	(RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
293 #define TABLE_MAIN_INDEX	(RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))
294 
295 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
296 {
297 	struct hlist_node *tb_hlist;
298 	struct hlist_head *ptr;
299 
300 	ptr = id == RT_TABLE_LOCAL ?
301 		&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
302 		&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
303 
304 	tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
305 
306 	return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
307 }
308 
309 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
310 {
311 	return fib_get_table(net, id);
312 }
313 
314 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
315 			     struct fib_result *res, unsigned int flags)
316 {
317 	struct fib_table *tb;
318 	int err = -ENETUNREACH;
319 
320 	rcu_read_lock();
321 
322 	tb = fib_get_table(net, RT_TABLE_MAIN);
323 	if (tb)
324 		err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
325 
326 	if (err == -EAGAIN)
327 		err = -ENETUNREACH;
328 
329 	rcu_read_unlock();
330 
331 	return err;
332 }
333 
334 static inline bool fib4_has_custom_rules(const struct net *net)
335 {
336 	return false;
337 }
338 
339 static inline bool fib4_rule_default(const struct fib_rule *rule)
340 {
341 	return true;
342 }
343 
344 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb,
345 				  struct netlink_ext_ack *extack)
346 {
347 	return 0;
348 }
349 
350 static inline unsigned int fib4_rules_seq_read(struct net *net)
351 {
352 	return 0;
353 }
354 
355 static inline bool fib4_rules_early_flow_dissect(struct net *net,
356 						 struct sk_buff *skb,
357 						 struct flowi4 *fl4,
358 						 struct flow_keys *flkeys)
359 {
360 	return false;
361 }
362 #else /* CONFIG_IP_MULTIPLE_TABLES */
363 int __net_init fib4_rules_init(struct net *net);
364 void __net_exit fib4_rules_exit(struct net *net);
365 
366 struct fib_table *fib_new_table(struct net *net, u32 id);
367 struct fib_table *fib_get_table(struct net *net, u32 id);
368 
369 int __fib_lookup(struct net *net, struct flowi4 *flp,
370 		 struct fib_result *res, unsigned int flags);
371 
372 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
373 			     struct fib_result *res, unsigned int flags)
374 {
375 	struct fib_table *tb;
376 	int err = -ENETUNREACH;
377 
378 	flags |= FIB_LOOKUP_NOREF;
379 	if (net->ipv4.fib_has_custom_rules)
380 		return __fib_lookup(net, flp, res, flags);
381 
382 	rcu_read_lock();
383 
384 	res->tclassid = 0;
385 
386 	tb = rcu_dereference_rtnl(net->ipv4.fib_main);
387 	if (tb)
388 		err = fib_table_lookup(tb, flp, res, flags);
389 
390 	if (!err)
391 		goto out;
392 
393 	tb = rcu_dereference_rtnl(net->ipv4.fib_default);
394 	if (tb)
395 		err = fib_table_lookup(tb, flp, res, flags);
396 
397 out:
398 	if (err == -EAGAIN)
399 		err = -ENETUNREACH;
400 
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(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 == inet_dsfield_to_dscp(RT_TOS(fl4->flowi4_tos));
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 			u8 tos, int oif, struct net_device *dev,
453 			struct in_device *idev, u32 *itag);
454 #ifdef CONFIG_IP_ROUTE_CLASSID
455 static inline int fib_num_tclassid_users(struct net *net)
456 {
457 	return atomic_read(&net->ipv4.fib_num_tclassid_users);
458 }
459 #else
460 static inline int fib_num_tclassid_users(struct net *net)
461 {
462 	return 0;
463 }
464 #endif
465 int fib_unmerge(struct net *net);
466 
467 static inline bool nhc_l3mdev_matches_dev(const struct fib_nh_common *nhc,
468 const struct net_device *dev)
469 {
470 	if (nhc->nhc_dev == dev ||
471 	    l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex)
472 		return true;
473 
474 	return false;
475 }
476 
477 /* Exported by fib_semantics.c */
478 int ip_fib_check_default(__be32 gw, struct net_device *dev);
479 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
480 int fib_sync_down_addr(struct net_device *dev, __be32 local);
481 int fib_sync_up(struct net_device *dev, unsigned char nh_flags);
482 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
483 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig);
484 
485 /* Fields used for sysctl_fib_multipath_hash_fields.
486  * Common to IPv4 and IPv6.
487  *
488  * Add new fields at the end. This is user API.
489  */
490 #define FIB_MULTIPATH_HASH_FIELD_SRC_IP			BIT(0)
491 #define FIB_MULTIPATH_HASH_FIELD_DST_IP			BIT(1)
492 #define FIB_MULTIPATH_HASH_FIELD_IP_PROTO		BIT(2)
493 #define FIB_MULTIPATH_HASH_FIELD_FLOWLABEL		BIT(3)
494 #define FIB_MULTIPATH_HASH_FIELD_SRC_PORT		BIT(4)
495 #define FIB_MULTIPATH_HASH_FIELD_DST_PORT		BIT(5)
496 #define FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP		BIT(6)
497 #define FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP		BIT(7)
498 #define FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO		BIT(8)
499 #define FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL	BIT(9)
500 #define FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT		BIT(10)
501 #define FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT		BIT(11)
502 
503 #define FIB_MULTIPATH_HASH_FIELD_OUTER_MASK		\
504 	(FIB_MULTIPATH_HASH_FIELD_SRC_IP |		\
505 	 FIB_MULTIPATH_HASH_FIELD_DST_IP |		\
506 	 FIB_MULTIPATH_HASH_FIELD_IP_PROTO |		\
507 	 FIB_MULTIPATH_HASH_FIELD_FLOWLABEL |		\
508 	 FIB_MULTIPATH_HASH_FIELD_SRC_PORT |		\
509 	 FIB_MULTIPATH_HASH_FIELD_DST_PORT)
510 
511 #define FIB_MULTIPATH_HASH_FIELD_INNER_MASK		\
512 	(FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP |	\
513 	 FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP |	\
514 	 FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO |	\
515 	 FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL |	\
516 	 FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT |	\
517 	 FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
518 
519 #define FIB_MULTIPATH_HASH_FIELD_ALL_MASK		\
520 	(FIB_MULTIPATH_HASH_FIELD_OUTER_MASK |		\
521 	 FIB_MULTIPATH_HASH_FIELD_INNER_MASK)
522 
523 #define FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK		\
524 	(FIB_MULTIPATH_HASH_FIELD_SRC_IP |		\
525 	 FIB_MULTIPATH_HASH_FIELD_DST_IP |		\
526 	 FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
527 
528 #ifdef CONFIG_IP_ROUTE_MULTIPATH
529 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
530 		       const struct sk_buff *skb, struct flow_keys *flkeys);
531 
532 static void
533 fib_multipath_hash_construct_key(siphash_key_t *key, u32 mp_seed)
534 {
535 	u64 mp_seed_64 = mp_seed;
536 
537 	key->key[0] = (mp_seed_64 << 32) | mp_seed_64;
538 	key->key[1] = key->key[0];
539 }
540 
541 static inline u32 fib_multipath_hash_from_keys(const struct net *net,
542 					       struct flow_keys *keys)
543 {
544 	siphash_aligned_key_t hash_key;
545 	u32 mp_seed;
546 
547 	mp_seed = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed).mp_seed;
548 	fib_multipath_hash_construct_key(&hash_key, mp_seed);
549 
550 	return flow_hash_from_keys_seed(keys, &hash_key);
551 }
552 #else
553 static inline u32 fib_multipath_hash_from_keys(const struct net *net,
554 					       struct flow_keys *keys)
555 {
556 	return flow_hash_from_keys(keys);
557 }
558 #endif
559 
560 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
561 		 struct netlink_ext_ack *extack);
562 void fib_select_multipath(struct fib_result *res, int hash);
563 void fib_select_path(struct net *net, struct fib_result *res,
564 		     struct flowi4 *fl4, const struct sk_buff *skb);
565 
566 int fib_nh_init(struct net *net, struct fib_nh *fib_nh,
567 		struct fib_config *cfg, int nh_weight,
568 		struct netlink_ext_ack *extack);
569 void fib_nh_release(struct net *net, struct fib_nh *fib_nh);
570 int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc,
571 		       struct nlattr *fc_encap, u16 fc_encap_type,
572 		       void *cfg, gfp_t gfp_flags,
573 		       struct netlink_ext_ack *extack);
574 void fib_nh_common_release(struct fib_nh_common *nhc);
575 
576 /* Exported by fib_trie.c */
577 void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri);
578 void fib_trie_init(void);
579 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
580 bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags,
581 			 const struct flowi4 *flp);
582 
583 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
584 {
585 #ifdef CONFIG_IP_ROUTE_CLASSID
586 	struct fib_nh_common *nhc = res->nhc;
587 #ifdef CONFIG_IP_MULTIPLE_TABLES
588 	u32 rtag;
589 #endif
590 	if (nhc->nhc_family == AF_INET) {
591 		struct fib_nh *nh;
592 
593 		nh = container_of(nhc, struct fib_nh, nh_common);
594 		*itag = nh->nh_tclassid << 16;
595 	} else {
596 		*itag = 0;
597 	}
598 
599 #ifdef CONFIG_IP_MULTIPLE_TABLES
600 	rtag = res->tclassid;
601 	if (*itag == 0)
602 		*itag = (rtag<<16);
603 	*itag |= (rtag>>16);
604 #endif
605 #endif
606 }
607 
608 void fib_flush(struct net *net);
609 void free_fib_info(struct fib_info *fi);
610 
611 static inline void fib_info_hold(struct fib_info *fi)
612 {
613 	refcount_inc(&fi->fib_clntref);
614 }
615 
616 static inline void fib_info_put(struct fib_info *fi)
617 {
618 	if (refcount_dec_and_test(&fi->fib_clntref))
619 		free_fib_info(fi);
620 }
621 
622 #ifdef CONFIG_PROC_FS
623 int __net_init fib_proc_init(struct net *net);
624 void __net_exit fib_proc_exit(struct net *net);
625 #else
626 static inline int fib_proc_init(struct net *net)
627 {
628 	return 0;
629 }
630 static inline void fib_proc_exit(struct net *net)
631 {
632 }
633 #endif
634 
635 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);
636 
637 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
638 			  struct fib_dump_filter *filter,
639 			  struct netlink_callback *cb);
640 
641 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh,
642 		     u8 rt_family, unsigned char *flags, bool skip_oif);
643 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh,
644 		    int nh_weight, u8 rt_family, u32 nh_tclassid);
645 #endif  /* _NET_FIB_H */
646