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
25 struct 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
55 struct fib_info;
56 struct rtable;
57
58 struct 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
72 struct 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
80 struct 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
103 struct 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
129 struct nexthop;
130
131 struct 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
161 struct fib_rule;
162 #endif
163
164 struct fib_table;
165 struct 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
178 struct 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
207 struct 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
217 struct fib_nh_notifier_info {
218 struct fib_notifier_info info; /* must be first */
219 struct fib_nh *fib_nh;
220 };
221
222 int call_fib4_notifier(struct notifier_block *nb, struct net *net,
223 enum fib_event_type event_type,
224 struct fib_notifier_info *info);
225 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
226 struct fib_notifier_info *info);
227
228 int __net_init fib4_notifier_init(struct net *net);
229 void __net_exit fib4_notifier_exit(struct net *net);
230
231 void fib_info_notify_update(struct net *net, struct nl_info *info);
232 void fib_notify(struct net *net, struct notifier_block *nb);
233
234 struct 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
243 struct 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_routes;
248 bool dump_exceptions;
249 unsigned char protocol;
250 unsigned char rt_type;
251 unsigned int flags;
252 struct net_device *dev;
253 };
254
255 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
256 struct fib_result *res, int fib_flags);
257 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
258 struct netlink_ext_ack *extack);
259 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
260 struct netlink_ext_ack *extack);
261 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
262 struct netlink_callback *cb, struct fib_dump_filter *filter);
263 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
264 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
265 void fib_table_flush_external(struct fib_table *table);
266 void fib_free_table(struct fib_table *tb);
267
268 #ifndef CONFIG_IP_MULTIPLE_TABLES
269
270 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
271 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
272
fib_get_table(struct net * net,u32 id)273 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
274 {
275 struct hlist_node *tb_hlist;
276 struct hlist_head *ptr;
277
278 ptr = id == RT_TABLE_LOCAL ?
279 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
280 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
281
282 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
283
284 return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
285 }
286
fib_new_table(struct net * net,u32 id)287 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
288 {
289 return fib_get_table(net, id);
290 }
291
fib_lookup(struct net * net,const struct flowi4 * flp,struct fib_result * res,unsigned int flags)292 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
293 struct fib_result *res, unsigned int flags)
294 {
295 struct fib_table *tb;
296 int err = -ENETUNREACH;
297
298 rcu_read_lock();
299
300 tb = fib_get_table(net, RT_TABLE_MAIN);
301 if (tb)
302 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
303
304 if (err == -EAGAIN)
305 err = -ENETUNREACH;
306
307 rcu_read_unlock();
308
309 return err;
310 }
311
fib4_rule_default(const struct fib_rule * rule)312 static inline bool fib4_rule_default(const struct fib_rule *rule)
313 {
314 return true;
315 }
316
fib4_rules_dump(struct net * net,struct notifier_block * nb)317 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb)
318 {
319 return 0;
320 }
321
fib4_rules_seq_read(struct net * net)322 static inline unsigned int fib4_rules_seq_read(struct net *net)
323 {
324 return 0;
325 }
326
fib4_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi4 * fl4,struct flow_keys * flkeys)327 static inline bool fib4_rules_early_flow_dissect(struct net *net,
328 struct sk_buff *skb,
329 struct flowi4 *fl4,
330 struct flow_keys *flkeys)
331 {
332 return false;
333 }
334 #else /* CONFIG_IP_MULTIPLE_TABLES */
335 int __net_init fib4_rules_init(struct net *net);
336 void __net_exit fib4_rules_exit(struct net *net);
337
338 struct fib_table *fib_new_table(struct net *net, u32 id);
339 struct fib_table *fib_get_table(struct net *net, u32 id);
340
341 int __fib_lookup(struct net *net, struct flowi4 *flp,
342 struct fib_result *res, unsigned int flags);
343
fib_lookup(struct net * net,struct flowi4 * flp,struct fib_result * res,unsigned int flags)344 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
345 struct fib_result *res, unsigned int flags)
346 {
347 struct fib_table *tb;
348 int err = -ENETUNREACH;
349
350 flags |= FIB_LOOKUP_NOREF;
351 if (net->ipv4.fib_has_custom_rules)
352 return __fib_lookup(net, flp, res, flags);
353
354 rcu_read_lock();
355
356 res->tclassid = 0;
357
358 tb = rcu_dereference_rtnl(net->ipv4.fib_main);
359 if (tb)
360 err = fib_table_lookup(tb, flp, res, flags);
361
362 if (!err)
363 goto out;
364
365 tb = rcu_dereference_rtnl(net->ipv4.fib_default);
366 if (tb)
367 err = fib_table_lookup(tb, flp, res, flags);
368
369 out:
370 if (err == -EAGAIN)
371 err = -ENETUNREACH;
372
373 rcu_read_unlock();
374
375 return err;
376 }
377
378 bool fib4_rule_default(const struct fib_rule *rule);
379 int fib4_rules_dump(struct net *net, struct notifier_block *nb);
380 unsigned int fib4_rules_seq_read(struct net *net);
381
fib4_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi4 * fl4,struct flow_keys * flkeys)382 static inline bool fib4_rules_early_flow_dissect(struct net *net,
383 struct sk_buff *skb,
384 struct flowi4 *fl4,
385 struct flow_keys *flkeys)
386 {
387 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
388
389 if (!net->ipv4.fib_rules_require_fldissect)
390 return false;
391
392 skb_flow_dissect_flow_keys(skb, flkeys, flag);
393 fl4->fl4_sport = flkeys->ports.src;
394 fl4->fl4_dport = flkeys->ports.dst;
395 fl4->flowi4_proto = flkeys->basic.ip_proto;
396
397 return true;
398 }
399
400 #endif /* CONFIG_IP_MULTIPLE_TABLES */
401
402 /* Exported by fib_frontend.c */
403 extern const struct nla_policy rtm_ipv4_policy[];
404 void ip_fib_init(void);
405 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
406 struct netlink_ext_ack *extack);
407 __be32 fib_compute_spec_dst(struct sk_buff *skb);
408 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev);
409 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
410 u8 tos, int oif, struct net_device *dev,
411 struct in_device *idev, u32 *itag);
412 #ifdef CONFIG_IP_ROUTE_CLASSID
fib_num_tclassid_users(struct net * net)413 static inline int fib_num_tclassid_users(struct net *net)
414 {
415 return atomic_read(&net->ipv4.fib_num_tclassid_users);
416 }
417 #else
fib_num_tclassid_users(struct net * net)418 static inline int fib_num_tclassid_users(struct net *net)
419 {
420 return 0;
421 }
422 #endif
423 int fib_unmerge(struct net *net);
424
nhc_l3mdev_matches_dev(const struct fib_nh_common * nhc,const struct net_device * dev)425 static inline bool nhc_l3mdev_matches_dev(const struct fib_nh_common *nhc,
426 const struct net_device *dev)
427 {
428 if (nhc->nhc_dev == dev ||
429 l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex)
430 return true;
431
432 return false;
433 }
434
435 /* Exported by fib_semantics.c */
436 int ip_fib_check_default(__be32 gw, struct net_device *dev);
437 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
438 int fib_sync_down_addr(struct net_device *dev, __be32 local);
439 int fib_sync_up(struct net_device *dev, unsigned char nh_flags);
440 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
441 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig);
442
443 #ifdef CONFIG_IP_ROUTE_MULTIPATH
444 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
445 const struct sk_buff *skb, struct flow_keys *flkeys);
446 #endif
447 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
448 struct netlink_ext_ack *extack);
449 void fib_select_multipath(struct fib_result *res, int hash);
450 void fib_select_path(struct net *net, struct fib_result *res,
451 struct flowi4 *fl4, const struct sk_buff *skb);
452
453 int fib_nh_init(struct net *net, struct fib_nh *fib_nh,
454 struct fib_config *cfg, int nh_weight,
455 struct netlink_ext_ack *extack);
456 void fib_nh_release(struct net *net, struct fib_nh *fib_nh);
457 int fib_nh_common_init(struct fib_nh_common *nhc, struct nlattr *fc_encap,
458 u16 fc_encap_type, void *cfg, gfp_t gfp_flags,
459 struct netlink_ext_ack *extack);
460 void fib_nh_common_release(struct fib_nh_common *nhc);
461
462 /* Exported by fib_trie.c */
463 void fib_trie_init(void);
464 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
465
fib_combine_itag(u32 * itag,const struct fib_result * res)466 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
467 {
468 #ifdef CONFIG_IP_ROUTE_CLASSID
469 struct fib_nh_common *nhc = res->nhc;
470 #ifdef CONFIG_IP_MULTIPLE_TABLES
471 u32 rtag;
472 #endif
473 if (nhc->nhc_family == AF_INET) {
474 struct fib_nh *nh;
475
476 nh = container_of(nhc, struct fib_nh, nh_common);
477 *itag = nh->nh_tclassid << 16;
478 } else {
479 *itag = 0;
480 }
481
482 #ifdef CONFIG_IP_MULTIPLE_TABLES
483 rtag = res->tclassid;
484 if (*itag == 0)
485 *itag = (rtag<<16);
486 *itag |= (rtag>>16);
487 #endif
488 #endif
489 }
490
491 void fib_flush(struct net *net);
492 void free_fib_info(struct fib_info *fi);
493
fib_info_hold(struct fib_info * fi)494 static inline void fib_info_hold(struct fib_info *fi)
495 {
496 refcount_inc(&fi->fib_clntref);
497 }
498
fib_info_put(struct fib_info * fi)499 static inline void fib_info_put(struct fib_info *fi)
500 {
501 if (refcount_dec_and_test(&fi->fib_clntref))
502 free_fib_info(fi);
503 }
504
505 #ifdef CONFIG_PROC_FS
506 int __net_init fib_proc_init(struct net *net);
507 void __net_exit fib_proc_exit(struct net *net);
508 #else
fib_proc_init(struct net * net)509 static inline int fib_proc_init(struct net *net)
510 {
511 return 0;
512 }
fib_proc_exit(struct net * net)513 static inline void fib_proc_exit(struct net *net)
514 {
515 }
516 #endif
517
518 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);
519
520 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
521 struct fib_dump_filter *filter,
522 struct netlink_callback *cb);
523
524 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh,
525 u8 rt_family, unsigned char *flags, bool skip_oif);
526 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh,
527 int nh_weight, u8 rt_family, u32 nh_tclassid);
528 #endif /* _NET_FIB_H */
529