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

source code of linux/include/net/ip_fib.h