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