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