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 struct rcu_head rcu;
127 struct fib_nh fib_nh[0];
128 #define fib_dev fib_nh[0].nh_dev
129 };
130
131
132 #ifdef CONFIG_IP_MULTIPLE_TABLES
133 struct fib_rule;
134 #endif
135
136 struct fib_table;
137 struct fib_result {
138 __be32 prefix;
139 unsigned char prefixlen;
140 unsigned char nh_sel;
141 unsigned char type;
142 unsigned char scope;
143 u32 tclassid;
144 struct fib_info *fi;
145 struct fib_table *table;
146 struct hlist_head *fa_head;
147 };
148
149 struct fib_result_nl {
150 __be32 fl_addr; /* To be looked up*/
151 u32 fl_mark;
152 unsigned char fl_tos;
153 unsigned char fl_scope;
154 unsigned char tb_id_in;
155
156 unsigned char tb_id; /* Results */
157 unsigned char prefixlen;
158 unsigned char nh_sel;
159 unsigned char type;
160 unsigned char scope;
161 int err;
162 };
163
164 #ifdef CONFIG_IP_ROUTE_MULTIPATH
165 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel])
166 #else /* CONFIG_IP_ROUTE_MULTIPATH */
167 #define FIB_RES_NH(res) ((res).fi->fib_nh[0])
168 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
169
170 #ifdef CONFIG_IP_MULTIPLE_TABLES
171 #define FIB_TABLE_HASHSZ 256
172 #else
173 #define FIB_TABLE_HASHSZ 2
174 #endif
175
176 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
177
178 #define FIB_RES_SADDR(net, res) \
179 ((FIB_RES_NH(res).nh_saddr_genid == \
180 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \
181 FIB_RES_NH(res).nh_saddr : \
182 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
183 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw)
184 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev)
185 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif)
186
187 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \
188 FIB_RES_SADDR(net, res))
189
190 struct fib_entry_notifier_info {
191 struct fib_notifier_info info; /* must be first */
192 u32 dst;
193 int dst_len;
194 struct fib_info *fi;
195 u8 tos;
196 u8 type;
197 u32 tb_id;
198 };
199
200 struct fib_nh_notifier_info {
201 struct fib_notifier_info info; /* must be first */
202 struct fib_nh *fib_nh;
203 };
204
205 int call_fib4_notifier(struct notifier_block *nb, struct net *net,
206 enum fib_event_type event_type,
207 struct fib_notifier_info *info);
208 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
209 struct fib_notifier_info *info);
210
211 int __net_init fib4_notifier_init(struct net *net);
212 void __net_exit fib4_notifier_exit(struct net *net);
213
214 void fib_notify(struct net *net, struct notifier_block *nb);
215
216 struct fib_table {
217 struct hlist_node tb_hlist;
218 u32 tb_id;
219 int tb_num_default;
220 struct rcu_head rcu;
221 unsigned long *tb_data;
222 unsigned long __data[0];
223 };
224
225 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
226 struct fib_result *res, int fib_flags);
227 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
228 struct netlink_ext_ack *extack);
229 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
230 struct netlink_ext_ack *extack);
231 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
232 struct netlink_callback *cb);
233 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
234 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
235 void fib_table_flush_external(struct fib_table *table);
236 void fib_free_table(struct fib_table *tb);
237
238 #ifndef CONFIG_IP_MULTIPLE_TABLES
239
240 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
241 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
242
fib_get_table(struct net * net,u32 id)243 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
244 {
245 struct hlist_node *tb_hlist;
246 struct hlist_head *ptr;
247
248 ptr = id == RT_TABLE_LOCAL ?
249 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
250 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
251
252 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
253
254 return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
255 }
256
fib_new_table(struct net * net,u32 id)257 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
258 {
259 return fib_get_table(net, id);
260 }
261
fib_lookup(struct net * net,const struct flowi4 * flp,struct fib_result * res,unsigned int flags)262 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
263 struct fib_result *res, unsigned int flags)
264 {
265 struct fib_table *tb;
266 int err = -ENETUNREACH;
267
268 rcu_read_lock();
269
270 tb = fib_get_table(net, RT_TABLE_MAIN);
271 if (tb)
272 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
273
274 if (err == -EAGAIN)
275 err = -ENETUNREACH;
276
277 rcu_read_unlock();
278
279 return err;
280 }
281
fib4_rule_default(const struct fib_rule * rule)282 static inline bool fib4_rule_default(const struct fib_rule *rule)
283 {
284 return true;
285 }
286
fib4_rules_dump(struct net * net,struct notifier_block * nb)287 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb)
288 {
289 return 0;
290 }
291
fib4_rules_seq_read(struct net * net)292 static inline unsigned int fib4_rules_seq_read(struct net *net)
293 {
294 return 0;
295 }
296
fib4_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi4 * fl4,struct flow_keys * flkeys)297 static inline bool fib4_rules_early_flow_dissect(struct net *net,
298 struct sk_buff *skb,
299 struct flowi4 *fl4,
300 struct flow_keys *flkeys)
301 {
302 return false;
303 }
304 #else /* CONFIG_IP_MULTIPLE_TABLES */
305 int __net_init fib4_rules_init(struct net *net);
306 void __net_exit fib4_rules_exit(struct net *net);
307
308 struct fib_table *fib_new_table(struct net *net, u32 id);
309 struct fib_table *fib_get_table(struct net *net, u32 id);
310
311 int __fib_lookup(struct net *net, struct flowi4 *flp,
312 struct fib_result *res, unsigned int flags);
313
fib_lookup(struct net * net,struct flowi4 * flp,struct fib_result * res,unsigned int flags)314 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
315 struct fib_result *res, unsigned int flags)
316 {
317 struct fib_table *tb;
318 int err = -ENETUNREACH;
319
320 flags |= FIB_LOOKUP_NOREF;
321 if (net->ipv4.fib_has_custom_rules)
322 return __fib_lookup(net, flp, res, flags);
323
324 rcu_read_lock();
325
326 res->tclassid = 0;
327
328 tb = rcu_dereference_rtnl(net->ipv4.fib_main);
329 if (tb)
330 err = fib_table_lookup(tb, flp, res, flags);
331
332 if (!err)
333 goto out;
334
335 tb = rcu_dereference_rtnl(net->ipv4.fib_default);
336 if (tb)
337 err = fib_table_lookup(tb, flp, res, flags);
338
339 out:
340 if (err == -EAGAIN)
341 err = -ENETUNREACH;
342
343 rcu_read_unlock();
344
345 return err;
346 }
347
348 bool fib4_rule_default(const struct fib_rule *rule);
349 int fib4_rules_dump(struct net *net, struct notifier_block *nb);
350 unsigned int fib4_rules_seq_read(struct net *net);
351
fib4_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi4 * fl4,struct flow_keys * flkeys)352 static inline bool fib4_rules_early_flow_dissect(struct net *net,
353 struct sk_buff *skb,
354 struct flowi4 *fl4,
355 struct flow_keys *flkeys)
356 {
357 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
358
359 if (!net->ipv4.fib_rules_require_fldissect)
360 return false;
361
362 skb_flow_dissect_flow_keys(skb, flkeys, flag);
363 fl4->fl4_sport = flkeys->ports.src;
364 fl4->fl4_dport = flkeys->ports.dst;
365 fl4->flowi4_proto = flkeys->basic.ip_proto;
366
367 return true;
368 }
369
370 #endif /* CONFIG_IP_MULTIPLE_TABLES */
371
372 /* Exported by fib_frontend.c */
373 extern const struct nla_policy rtm_ipv4_policy[];
374 void ip_fib_init(void);
375 __be32 fib_compute_spec_dst(struct sk_buff *skb);
376 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
377 u8 tos, int oif, struct net_device *dev,
378 struct in_device *idev, u32 *itag);
379 #ifdef CONFIG_IP_ROUTE_CLASSID
fib_num_tclassid_users(struct net * net)380 static inline int fib_num_tclassid_users(struct net *net)
381 {
382 return net->ipv4.fib_num_tclassid_users;
383 }
384 #else
fib_num_tclassid_users(struct net * net)385 static inline int fib_num_tclassid_users(struct net *net)
386 {
387 return 0;
388 }
389 #endif
390 int fib_unmerge(struct net *net);
391
392 /* Exported by fib_semantics.c */
393 int ip_fib_check_default(__be32 gw, struct net_device *dev);
394 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
395 int fib_sync_down_addr(struct net_device *dev, __be32 local);
396 int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
397 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
398
399 #ifdef CONFIG_IP_ROUTE_MULTIPATH
400 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
401 const struct sk_buff *skb, struct flow_keys *flkeys);
402 #endif
403 void fib_select_multipath(struct fib_result *res, int hash);
404 void fib_select_path(struct net *net, struct fib_result *res,
405 struct flowi4 *fl4, const struct sk_buff *skb);
406
407 /* Exported by fib_trie.c */
408 void fib_trie_init(void);
409 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
410
fib_combine_itag(u32 * itag,const struct fib_result * res)411 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
412 {
413 #ifdef CONFIG_IP_ROUTE_CLASSID
414 #ifdef CONFIG_IP_MULTIPLE_TABLES
415 u32 rtag;
416 #endif
417 *itag = FIB_RES_NH(*res).nh_tclassid<<16;
418 #ifdef CONFIG_IP_MULTIPLE_TABLES
419 rtag = res->tclassid;
420 if (*itag == 0)
421 *itag = (rtag<<16);
422 *itag |= (rtag>>16);
423 #endif
424 #endif
425 }
426
427 void free_fib_info(struct fib_info *fi);
428
fib_info_hold(struct fib_info * fi)429 static inline void fib_info_hold(struct fib_info *fi)
430 {
431 refcount_inc(&fi->fib_clntref);
432 }
433
fib_info_put(struct fib_info * fi)434 static inline void fib_info_put(struct fib_info *fi)
435 {
436 if (refcount_dec_and_test(&fi->fib_clntref))
437 free_fib_info(fi);
438 }
439
440 #ifdef CONFIG_PROC_FS
441 int __net_init fib_proc_init(struct net *net);
442 void __net_exit fib_proc_exit(struct net *net);
443 #else
fib_proc_init(struct net * net)444 static inline int fib_proc_init(struct net *net)
445 {
446 return 0;
447 }
fib_proc_exit(struct net * net)448 static inline void fib_proc_exit(struct net *net)
449 {
450 }
451 #endif
452
453 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);
454
455 #endif /* _NET_FIB_H */
456