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_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
256 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
257 struct fib_result *res, int fib_flags);
258 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
259 struct netlink_ext_ack *extack);
260 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
261 struct netlink_ext_ack *extack);
262 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
263 struct netlink_callback *cb, struct fib_dump_filter *filter);
264 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
265 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
266 void fib_table_flush_external(struct fib_table *table);
267 void 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
fib_get_table(struct net * net,u32 id)274 static 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
fib_new_table(struct net * net,u32 id)288 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
289 {
290 return fib_get_table(net, id);
291 }
292
fib_lookup(struct net * net,const struct flowi4 * flp,struct fib_result * res,unsigned int flags)293 static 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
fib4_rule_default(const struct fib_rule * rule)313 static inline bool fib4_rule_default(const struct fib_rule *rule)
314 {
315 return true;
316 }
317
fib4_rules_dump(struct net * net,struct notifier_block * nb)318 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb)
319 {
320 return 0;
321 }
322
fib4_rules_seq_read(struct net * net)323 static inline unsigned int fib4_rules_seq_read(struct net *net)
324 {
325 return 0;
326 }
327
fib4_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi4 * fl4,struct flow_keys * flkeys)328 static 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 */
336 int __net_init fib4_rules_init(struct net *net);
337 void __net_exit fib4_rules_exit(struct net *net);
338
339 struct fib_table *fib_new_table(struct net *net, u32 id);
340 struct fib_table *fib_get_table(struct net *net, u32 id);
341
342 int __fib_lookup(struct net *net, struct flowi4 *flp,
343 struct fib_result *res, unsigned int flags);
344
fib_lookup(struct net * net,struct flowi4 * flp,struct fib_result * res,unsigned int flags)345 static 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
370 out:
371 if (err == -EAGAIN)
372 err = -ENETUNREACH;
373
374 rcu_read_unlock();
375
376 return err;
377 }
378
379 bool fib4_rule_default(const struct fib_rule *rule);
380 int fib4_rules_dump(struct net *net, struct notifier_block *nb);
381 unsigned int fib4_rules_seq_read(struct net *net);
382
fib4_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi4 * fl4,struct flow_keys * flkeys)383 static 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 */
404 extern const struct nla_policy rtm_ipv4_policy[];
405 void ip_fib_init(void);
406 int 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);
409 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev);
410 int 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
fib_num_tclassid_users(struct net * net)414 static inline int fib_num_tclassid_users(struct net *net)
415 {
416 return net->ipv4.fib_num_tclassid_users;
417 }
418 #else
fib_num_tclassid_users(struct net * net)419 static inline int fib_num_tclassid_users(struct net *net)
420 {
421 return 0;
422 }
423 #endif
424 int fib_unmerge(struct net *net);
425
426 /* Exported by fib_semantics.c */
427 int ip_fib_check_default(__be32 gw, struct net_device *dev);
428 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
429 int fib_sync_down_addr(struct net_device *dev, __be32 local);
430 int fib_sync_up(struct net_device *dev, unsigned char nh_flags);
431 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
432 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig);
433
434 #ifdef CONFIG_IP_ROUTE_MULTIPATH
435 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
436 const struct sk_buff *skb, struct flow_keys *flkeys);
437 #endif
438 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
439 struct netlink_ext_ack *extack);
440 void fib_select_multipath(struct fib_result *res, int hash);
441 void fib_select_path(struct net *net, struct fib_result *res,
442 struct flowi4 *fl4, const struct sk_buff *skb);
443
444 int 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);
447 void fib_nh_release(struct net *net, struct fib_nh *fib_nh);
448 int 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);
451 void fib_nh_common_release(struct fib_nh_common *nhc);
452
453 /* Exported by fib_trie.c */
454 void fib_trie_init(void);
455 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
456
fib_combine_itag(u32 * itag,const struct fib_result * res)457 static 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
482 void fib_flush(struct net *net);
483 void free_fib_info(struct fib_info *fi);
484
fib_info_hold(struct fib_info * fi)485 static inline void fib_info_hold(struct fib_info *fi)
486 {
487 refcount_inc(&fi->fib_clntref);
488 }
489
fib_info_put(struct fib_info * fi)490 static 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
497 int __net_init fib_proc_init(struct net *net);
498 void __net_exit fib_proc_exit(struct net *net);
499 #else
fib_proc_init(struct net * net)500 static inline int fib_proc_init(struct net *net)
501 {
502 return 0;
503 }
fib_proc_exit(struct net * net)504 static inline void fib_proc_exit(struct net *net)
505 {
506 }
507 #endif
508
509 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);
510
511 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
512 struct fib_dump_filter *filter,
513 struct netlink_callback *cb);
514
515 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh,
516 u8 rt_family, unsigned char *flags, bool skip_oif);
517 int 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 */
520