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
29struct 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
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 {
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
106struct 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
133struct fib_rule;
134#endif
135
136struct fib_table;
137struct 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
149struct 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
190struct 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
200struct fib_nh_notifier_info {
201 struct fib_notifier_info info; /* must be first */
202 struct fib_nh *fib_nh;
203};
204
205int call_fib4_notifier(struct notifier_block *nb, struct net *net,
206 enum fib_event_type event_type,
207 struct fib_notifier_info *info);
208int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
209 struct fib_notifier_info *info);
210
211int __net_init fib4_notifier_init(struct net *net);
212void __net_exit fib4_notifier_exit(struct net *net);
213
214void fib_notify(struct net *net, struct notifier_block *nb);
215
216struct 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
225struct fib_dump_filter {
226 u32 table_id;
227 /* filter_set is an optimization that an entry is set */
228 bool filter_set;
229 bool dump_all_families;
230 unsigned char protocol;
231 unsigned char rt_type;
232 unsigned int flags;
233 struct net_device *dev;
234};
235
236int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
237 struct fib_result *res, int fib_flags);
238int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
239 struct netlink_ext_ack *extack);
240int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
241 struct netlink_ext_ack *extack);
242int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
243 struct netlink_callback *cb, struct fib_dump_filter *filter);
244int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
245struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
246void fib_table_flush_external(struct fib_table *table);
247void fib_free_table(struct fib_table *tb);
248
249#ifndef CONFIG_IP_MULTIPLE_TABLES
250
251#define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
252#define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
253
254static inline struct fib_table *fib_get_table(struct net *net, u32 id)
255{
256 struct hlist_node *tb_hlist;
257 struct hlist_head *ptr;
258
259 ptr = id == RT_TABLE_LOCAL ?
260 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
261 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
262
263 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
264
265 return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
266}
267
268static inline struct fib_table *fib_new_table(struct net *net, u32 id)
269{
270 return fib_get_table(net, id);
271}
272
273static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
274 struct fib_result *res, unsigned int flags)
275{
276 struct fib_table *tb;
277 int err = -ENETUNREACH;
278
279 rcu_read_lock();
280
281 tb = fib_get_table(net, RT_TABLE_MAIN);
282 if (tb)
283 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
284
285 if (err == -EAGAIN)
286 err = -ENETUNREACH;
287
288 rcu_read_unlock();
289
290 return err;
291}
292
293static inline bool fib4_rule_default(const struct fib_rule *rule)
294{
295 return true;
296}
297
298static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb)
299{
300 return 0;
301}
302
303static inline unsigned int fib4_rules_seq_read(struct net *net)
304{
305 return 0;
306}
307
308static inline bool fib4_rules_early_flow_dissect(struct net *net,
309 struct sk_buff *skb,
310 struct flowi4 *fl4,
311 struct flow_keys *flkeys)
312{
313 return false;
314}
315#else /* CONFIG_IP_MULTIPLE_TABLES */
316int __net_init fib4_rules_init(struct net *net);
317void __net_exit fib4_rules_exit(struct net *net);
318
319struct fib_table *fib_new_table(struct net *net, u32 id);
320struct fib_table *fib_get_table(struct net *net, u32 id);
321
322int __fib_lookup(struct net *net, struct flowi4 *flp,
323 struct fib_result *res, unsigned int flags);
324
325static inline int fib_lookup(struct net *net, struct flowi4 *flp,
326 struct fib_result *res, unsigned int flags)
327{
328 struct fib_table *tb;
329 int err = -ENETUNREACH;
330
331 flags |= FIB_LOOKUP_NOREF;
332 if (net->ipv4.fib_has_custom_rules)
333 return __fib_lookup(net, flp, res, flags);
334
335 rcu_read_lock();
336
337 res->tclassid = 0;
338
339 tb = rcu_dereference_rtnl(net->ipv4.fib_main);
340 if (tb)
341 err = fib_table_lookup(tb, flp, res, flags);
342
343 if (!err)
344 goto out;
345
346 tb = rcu_dereference_rtnl(net->ipv4.fib_default);
347 if (tb)
348 err = fib_table_lookup(tb, flp, res, flags);
349
350out:
351 if (err == -EAGAIN)
352 err = -ENETUNREACH;
353
354 rcu_read_unlock();
355
356 return err;
357}
358
359bool fib4_rule_default(const struct fib_rule *rule);
360int fib4_rules_dump(struct net *net, struct notifier_block *nb);
361unsigned int fib4_rules_seq_read(struct net *net);
362
363static inline bool fib4_rules_early_flow_dissect(struct net *net,
364 struct sk_buff *skb,
365 struct flowi4 *fl4,
366 struct flow_keys *flkeys)
367{
368 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
369
370 if (!net->ipv4.fib_rules_require_fldissect)
371 return false;
372
373 skb_flow_dissect_flow_keys(skb, flkeys, flag);
374 fl4->fl4_sport = flkeys->ports.src;
375 fl4->fl4_dport = flkeys->ports.dst;
376 fl4->flowi4_proto = flkeys->basic.ip_proto;
377
378 return true;
379}
380
381#endif /* CONFIG_IP_MULTIPLE_TABLES */
382
383/* Exported by fib_frontend.c */
384extern const struct nla_policy rtm_ipv4_policy[];
385void ip_fib_init(void);
386__be32 fib_compute_spec_dst(struct sk_buff *skb);
387bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev);
388int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
389 u8 tos, int oif, struct net_device *dev,
390 struct in_device *idev, u32 *itag);
391#ifdef CONFIG_IP_ROUTE_CLASSID
392static inline int fib_num_tclassid_users(struct net *net)
393{
394 return net->ipv4.fib_num_tclassid_users;
395}
396#else
397static inline int fib_num_tclassid_users(struct net *net)
398{
399 return 0;
400}
401#endif
402int fib_unmerge(struct net *net);
403
404/* Exported by fib_semantics.c */
405int ip_fib_check_default(__be32 gw, struct net_device *dev);
406int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
407int fib_sync_down_addr(struct net_device *dev, __be32 local);
408int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
409void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
410
411#ifdef CONFIG_IP_ROUTE_MULTIPATH
412int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
413 const struct sk_buff *skb, struct flow_keys *flkeys);
414#endif
415void fib_select_multipath(struct fib_result *res, int hash);
416void fib_select_path(struct net *net, struct fib_result *res,
417 struct flowi4 *fl4, const struct sk_buff *skb);
418
419/* Exported by fib_trie.c */
420void fib_trie_init(void);
421struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
422
423static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
424{
425#ifdef CONFIG_IP_ROUTE_CLASSID
426#ifdef CONFIG_IP_MULTIPLE_TABLES
427 u32 rtag;
428#endif
429 *itag = FIB_RES_NH(*res).nh_tclassid<<16;
430#ifdef CONFIG_IP_MULTIPLE_TABLES
431 rtag = res->tclassid;
432 if (*itag == 0)
433 *itag = (rtag<<16);
434 *itag |= (rtag>>16);
435#endif
436#endif
437}
438
439void free_fib_info(struct fib_info *fi);
440
441static inline void fib_info_hold(struct fib_info *fi)
442{
443 refcount_inc(&fi->fib_clntref);
444}
445
446static inline void fib_info_put(struct fib_info *fi)
447{
448 if (refcount_dec_and_test(&fi->fib_clntref))
449 free_fib_info(fi);
450}
451
452#ifdef CONFIG_PROC_FS
453int __net_init fib_proc_init(struct net *net);
454void __net_exit fib_proc_exit(struct net *net);
455#else
456static inline int fib_proc_init(struct net *net)
457{
458 return 0;
459}
460static inline void fib_proc_exit(struct net *net)
461{
462}
463#endif
464
465u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);
466
467int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
468 struct fib_dump_filter *filter,
469 struct netlink_callback *cb);
470#endif /* _NET_FIB_H */
471