1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Definitions for the Forwarding Information Base.
7 *
8 * Authors: A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15
16 #ifndef _NET_IP_FIB_H
17 #define _NET_IP_FIB_H
18
19 #include <net/flow.h>
20 #include <linux/seq_file.h>
21 #include <linux/rcupdate.h>
22 #include <net/fib_notifier.h>
23 #include <net/fib_rules.h>
24 #include <net/inetpeer.h>
25 #include <linux/percpu.h>
26 #include <linux/notifier.h>
27 #include <linux/refcount.h>
28
29 struct fib_config {
30 u8 fc_dst_len;
31 u8 fc_tos;
32 u8 fc_protocol;
33 u8 fc_scope;
34 u8 fc_type;
35 /* 3 bytes unused */
36 u32 fc_table;
37 __be32 fc_dst;
38 __be32 fc_gw;
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
54 struct fib_info;
55 struct rtable;
56
57 struct 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
71 struct 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
79 struct fib_nh {
80 struct net_device *nh_dev;
81 struct hlist_node nh_hash;
82 struct fib_info *nh_parent;
83 unsigned int nh_flags;
84 unsigned char nh_scope;
85 #ifdef CONFIG_IP_ROUTE_MULTIPATH
86 int nh_weight;
87 atomic_t nh_upper_bound;
88 #endif
89 #ifdef CONFIG_IP_ROUTE_CLASSID
90 __u32 nh_tclassid;
91 #endif
92 int nh_oif;
93 __be32 nh_gw;
94 __be32 nh_saddr;
95 int nh_saddr_genid;
96 struct rtable __rcu * __percpu *nh_pcpu_rth_output;
97 struct rtable __rcu *nh_rth_input;
98 struct fnhe_hash_bucket __rcu *nh_exceptions;
99 struct lwtunnel_state *nh_lwtstate;
100 };
101
102 /*
103 * This structure contains data shared by many of routes.
104 */
105
106 struct fib_info {
107 struct hlist_node fib_hash;
108 struct hlist_node fib_lhash;
109 struct net *fib_net;
110 int fib_treeref;
111 refcount_t fib_clntref;
112 unsigned int fib_flags;
113 unsigned char fib_dead;
114 unsigned char fib_protocol;
115 unsigned char fib_scope;
116 unsigned char fib_type;
117 __be32 fib_prefsrc;
118 u32 fib_tb_id;
119 u32 fib_priority;
120 struct dst_metrics *fib_metrics;
121 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1]
122 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1]
123 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1]
124 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
125 int fib_nhs;
126 #ifdef CONFIG_IP_ROUTE_MULTIPATH
127 int fib_weight;
128 #endif
129 struct rcu_head rcu;
130 struct fib_nh fib_nh[0];
131 #define fib_dev fib_nh[0].nh_dev
132 };
133
134
135 #ifdef CONFIG_IP_MULTIPLE_TABLES
136 struct fib_rule;
137 #endif
138
139 struct fib_table;
140 struct fib_result {
141 __be32 prefix;
142 unsigned char prefixlen;
143 unsigned char nh_sel;
144 unsigned char type;
145 unsigned char scope;
146 u32 tclassid;
147 struct fib_info *fi;
148 struct fib_table *table;
149 struct hlist_head *fa_head;
150 };
151
152 struct fib_result_nl {
153 __be32 fl_addr; /* To be looked up*/
154 u32 fl_mark;
155 unsigned char fl_tos;
156 unsigned char fl_scope;
157 unsigned char tb_id_in;
158
159 unsigned char tb_id; /* Results */
160 unsigned char prefixlen;
161 unsigned char nh_sel;
162 unsigned char type;
163 unsigned char scope;
164 int err;
165 };
166
167 #ifdef CONFIG_IP_ROUTE_MULTIPATH
168 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel])
169 #else /* CONFIG_IP_ROUTE_MULTIPATH */
170 #define FIB_RES_NH(res) ((res).fi->fib_nh[0])
171 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
172
173 #ifdef CONFIG_IP_MULTIPLE_TABLES
174 #define FIB_TABLE_HASHSZ 256
175 #else
176 #define FIB_TABLE_HASHSZ 2
177 #endif
178
179 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
180
181 #define FIB_RES_SADDR(net, res) \
182 ((FIB_RES_NH(res).nh_saddr_genid == \
183 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \
184 FIB_RES_NH(res).nh_saddr : \
185 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
186 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw)
187 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev)
188 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif)
189
190 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \
191 FIB_RES_SADDR(net, res))
192
193 struct fib_entry_notifier_info {
194 struct fib_notifier_info info; /* must be first */
195 u32 dst;
196 int dst_len;
197 struct fib_info *fi;
198 u8 tos;
199 u8 type;
200 u32 tb_id;
201 };
202
203 struct fib_nh_notifier_info {
204 struct fib_notifier_info info; /* must be first */
205 struct fib_nh *fib_nh;
206 };
207
208 int call_fib4_notifier(struct notifier_block *nb, struct net *net,
209 enum fib_event_type event_type,
210 struct fib_notifier_info *info);
211 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
212 struct fib_notifier_info *info);
213
214 int __net_init fib4_notifier_init(struct net *net);
215 void __net_exit fib4_notifier_exit(struct net *net);
216
217 void fib_notify(struct net *net, struct notifier_block *nb);
218
219 struct fib_table {
220 struct hlist_node tb_hlist;
221 u32 tb_id;
222 int tb_num_default;
223 struct rcu_head rcu;
224 unsigned long *tb_data;
225 unsigned long __data[0];
226 };
227
228 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
229 struct fib_result *res, int fib_flags);
230 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
231 struct netlink_ext_ack *extack);
232 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
233 struct netlink_ext_ack *extack);
234 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
235 struct netlink_callback *cb);
236 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
237 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
238 void fib_table_flush_external(struct fib_table *table);
239 void fib_free_table(struct fib_table *tb);
240
241 #ifndef CONFIG_IP_MULTIPLE_TABLES
242
243 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
244 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
245
fib_get_table(struct net * net,u32 id)246 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
247 {
248 struct hlist_node *tb_hlist;
249 struct hlist_head *ptr;
250
251 ptr = id == RT_TABLE_LOCAL ?
252 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
253 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
254
255 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
256
257 return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
258 }
259
fib_new_table(struct net * net,u32 id)260 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
261 {
262 return fib_get_table(net, id);
263 }
264
fib_lookup(struct net * net,const struct flowi4 * flp,struct fib_result * res,unsigned int flags)265 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
266 struct fib_result *res, unsigned int flags)
267 {
268 struct fib_table *tb;
269 int err = -ENETUNREACH;
270
271 rcu_read_lock();
272
273 tb = fib_get_table(net, RT_TABLE_MAIN);
274 if (tb)
275 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
276
277 if (err == -EAGAIN)
278 err = -ENETUNREACH;
279
280 rcu_read_unlock();
281
282 return err;
283 }
284
fib4_rule_default(const struct fib_rule * rule)285 static inline bool fib4_rule_default(const struct fib_rule *rule)
286 {
287 return true;
288 }
289
fib4_rules_dump(struct net * net,struct notifier_block * nb)290 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb)
291 {
292 return 0;
293 }
294
fib4_rules_seq_read(struct net * net)295 static inline unsigned int fib4_rules_seq_read(struct net *net)
296 {
297 return 0;
298 }
299
300 #else /* CONFIG_IP_MULTIPLE_TABLES */
301 int __net_init fib4_rules_init(struct net *net);
302 void __net_exit fib4_rules_exit(struct net *net);
303
304 struct fib_table *fib_new_table(struct net *net, u32 id);
305 struct fib_table *fib_get_table(struct net *net, u32 id);
306
307 int __fib_lookup(struct net *net, struct flowi4 *flp,
308 struct fib_result *res, unsigned int flags);
309
fib_lookup(struct net * net,struct flowi4 * flp,struct fib_result * res,unsigned int flags)310 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
311 struct fib_result *res, unsigned int flags)
312 {
313 struct fib_table *tb;
314 int err = -ENETUNREACH;
315
316 flags |= FIB_LOOKUP_NOREF;
317 if (net->ipv4.fib_has_custom_rules)
318 return __fib_lookup(net, flp, res, flags);
319
320 rcu_read_lock();
321
322 res->tclassid = 0;
323
324 tb = rcu_dereference_rtnl(net->ipv4.fib_main);
325 if (tb)
326 err = fib_table_lookup(tb, flp, res, flags);
327
328 if (!err)
329 goto out;
330
331 tb = rcu_dereference_rtnl(net->ipv4.fib_default);
332 if (tb)
333 err = fib_table_lookup(tb, flp, res, flags);
334
335 out:
336 if (err == -EAGAIN)
337 err = -ENETUNREACH;
338
339 rcu_read_unlock();
340
341 return err;
342 }
343
344 bool fib4_rule_default(const struct fib_rule *rule);
345 int fib4_rules_dump(struct net *net, struct notifier_block *nb);
346 unsigned int fib4_rules_seq_read(struct net *net);
347
348 #endif /* CONFIG_IP_MULTIPLE_TABLES */
349
350 /* Exported by fib_frontend.c */
351 extern const struct nla_policy rtm_ipv4_policy[];
352 void ip_fib_init(void);
353 __be32 fib_compute_spec_dst(struct sk_buff *skb);
354 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
355 u8 tos, int oif, struct net_device *dev,
356 struct in_device *idev, u32 *itag);
357 #ifdef CONFIG_IP_ROUTE_CLASSID
fib_num_tclassid_users(struct net * net)358 static inline int fib_num_tclassid_users(struct net *net)
359 {
360 return net->ipv4.fib_num_tclassid_users;
361 }
362 #else
fib_num_tclassid_users(struct net * net)363 static inline int fib_num_tclassid_users(struct net *net)
364 {
365 return 0;
366 }
367 #endif
368 int fib_unmerge(struct net *net);
369
370 /* Exported by fib_semantics.c */
371 int ip_fib_check_default(__be32 gw, struct net_device *dev);
372 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
373 int fib_sync_down_addr(struct net_device *dev, __be32 local);
374 int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
375 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
376
377 #ifdef CONFIG_IP_ROUTE_MULTIPATH
378 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
379 const struct sk_buff *skb);
380 #endif
381 void fib_select_multipath(struct fib_result *res, int hash);
382 void fib_select_path(struct net *net, struct fib_result *res,
383 struct flowi4 *fl4, const struct sk_buff *skb);
384
385 /* Exported by fib_trie.c */
386 void fib_trie_init(void);
387 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
388
fib_combine_itag(u32 * itag,const struct fib_result * res)389 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
390 {
391 #ifdef CONFIG_IP_ROUTE_CLASSID
392 #ifdef CONFIG_IP_MULTIPLE_TABLES
393 u32 rtag;
394 #endif
395 *itag = FIB_RES_NH(*res).nh_tclassid<<16;
396 #ifdef CONFIG_IP_MULTIPLE_TABLES
397 rtag = res->tclassid;
398 if (*itag == 0)
399 *itag = (rtag<<16);
400 *itag |= (rtag>>16);
401 #endif
402 #endif
403 }
404
405 void free_fib_info(struct fib_info *fi);
406
fib_info_hold(struct fib_info * fi)407 static inline void fib_info_hold(struct fib_info *fi)
408 {
409 refcount_inc(&fi->fib_clntref);
410 }
411
fib_info_put(struct fib_info * fi)412 static inline void fib_info_put(struct fib_info *fi)
413 {
414 if (refcount_dec_and_test(&fi->fib_clntref))
415 free_fib_info(fi);
416 }
417
418 #ifdef CONFIG_PROC_FS
419 int __net_init fib_proc_init(struct net *net);
420 void __net_exit fib_proc_exit(struct net *net);
421 #else
fib_proc_init(struct net * net)422 static inline int fib_proc_init(struct net *net)
423 {
424 return 0;
425 }
fib_proc_exit(struct net * net)426 static inline void fib_proc_exit(struct net *net)
427 {
428 }
429 #endif
430
431 #endif /* _NET_FIB_H */
432