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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_rules.h>
23#include <net/inetpeer.h>
24#include <linux/percpu.h>
25
26struct fib_config {
27 u8 fc_dst_len;
28 u8 fc_tos;
29 u8 fc_protocol;
30 u8 fc_scope;
31 u8 fc_type;
32 /* 3 bytes unused */
33 u32 fc_table;
34 __be32 fc_dst;
35 __be32 fc_gw;
36 int fc_oif;
37 u32 fc_flags;
38 u32 fc_priority;
39 __be32 fc_prefsrc;
40 struct nlattr *fc_mx;
41 struct rtnexthop *fc_mp;
42 int fc_mx_len;
43 int fc_mp_len;
44 u32 fc_flow;
45 u32 fc_nlflags;
46 struct nl_info fc_nlinfo;
47 };
48
49struct fib_info;
50struct rtable;
51
52struct fib_nh_exception {
53 struct fib_nh_exception __rcu *fnhe_next;
54 int fnhe_genid;
55 __be32 fnhe_daddr;
56 u32 fnhe_pmtu;
57 __be32 fnhe_gw;
58 unsigned long fnhe_expires;
59 struct rtable __rcu *fnhe_rth_input;
60 struct rtable __rcu *fnhe_rth_output;
61 unsigned long fnhe_stamp;
62};
63
64struct fnhe_hash_bucket {
65 struct fib_nh_exception __rcu *chain;
66};
67
68#define FNHE_HASH_SHIFT 11
69#define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT)
70#define FNHE_RECLAIM_DEPTH 5
71
72struct fib_nh {
73 struct net_device *nh_dev;
74 struct hlist_node nh_hash;
75 struct fib_info *nh_parent;
76 unsigned int nh_flags;
77 unsigned char nh_scope;
78#ifdef CONFIG_IP_ROUTE_MULTIPATH
79 int nh_weight;
80 int nh_power;
81#endif
82#ifdef CONFIG_IP_ROUTE_CLASSID
83 __u32 nh_tclassid;
84#endif
85 int nh_oif;
86 __be32 nh_gw;
87 __be32 nh_saddr;
88 int nh_saddr_genid;
89 struct rtable __rcu * __percpu *nh_pcpu_rth_output;
90 struct rtable __rcu *nh_rth_input;
91 struct fnhe_hash_bucket __rcu *nh_exceptions;
92};
93
94/*
95 * This structure contains data shared by many of routes.
96 */
97
98struct fib_info {
99 struct hlist_node fib_hash;
100 struct hlist_node fib_lhash;
101 struct net *fib_net;
102 int fib_treeref;
103 atomic_t fib_clntref;
104 unsigned int fib_flags;
105 unsigned char fib_dead;
106 unsigned char fib_protocol;
107 unsigned char fib_scope;
108 unsigned char fib_type;
109 __be32 fib_prefsrc;
110 u32 fib_priority;
111 u32 *fib_metrics;
112#define fib_mtu fib_metrics[RTAX_MTU-1]
113#define fib_window fib_metrics[RTAX_WINDOW-1]
114#define fib_rtt fib_metrics[RTAX_RTT-1]
115#define fib_advmss fib_metrics[RTAX_ADVMSS-1]
116 int fib_nhs;
117#ifdef CONFIG_IP_ROUTE_MULTIPATH
118 int fib_power;
119#endif
120 struct rcu_head rcu;
121 struct fib_nh fib_nh[0];
122#define fib_dev fib_nh[0].nh_dev
123};
124
125
126#ifdef CONFIG_IP_MULTIPLE_TABLES
127struct fib_rule;
128#endif
129
130struct fib_table;
131struct fib_result {
132 unsigned char prefixlen;
133 unsigned char nh_sel;
134 unsigned char type;
135 unsigned char scope;
136 u32 tclassid;
137 struct fib_info *fi;
138 struct fib_table *table;
139 struct hlist_head *fa_head;
140};
141
142struct fib_result_nl {
143 __be32 fl_addr; /* To be looked up*/
144 u32 fl_mark;
145 unsigned char fl_tos;
146 unsigned char fl_scope;
147 unsigned char tb_id_in;
148
149 unsigned char tb_id; /* Results */
150 unsigned char prefixlen;
151 unsigned char nh_sel;
152 unsigned char type;
153 unsigned char scope;
154 int err;
155};
156
157#ifdef CONFIG_IP_ROUTE_MULTIPATH
158#define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel])
159#else /* CONFIG_IP_ROUTE_MULTIPATH */
160#define FIB_RES_NH(res) ((res).fi->fib_nh[0])
161#endif /* CONFIG_IP_ROUTE_MULTIPATH */
162
163#ifdef CONFIG_IP_MULTIPLE_TABLES
164#define FIB_TABLE_HASHSZ 256
165#else
166#define FIB_TABLE_HASHSZ 2
167#endif
168
169__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
170
171#define FIB_RES_SADDR(net, res) \
172 ((FIB_RES_NH(res).nh_saddr_genid == \
173 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \
174 FIB_RES_NH(res).nh_saddr : \
175 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
176#define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw)
177#define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev)
178#define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif)
179
180#define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \
181 FIB_RES_SADDR(net, res))
182
183struct fib_table {
184 struct hlist_node tb_hlist;
185 u32 tb_id;
186 int tb_num_default;
187 struct rcu_head rcu;
188 unsigned long *tb_data;
189 unsigned long __data[0];
190};
191
192int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
193 struct fib_result *res, int fib_flags);
194int fib_table_insert(struct fib_table *, struct fib_config *);
195int fib_table_delete(struct fib_table *, struct fib_config *);
196int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
197 struct netlink_callback *cb);
198int fib_table_flush(struct fib_table *table);
199struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
200void fib_table_flush_external(struct fib_table *table);
201void fib_free_table(struct fib_table *tb);
202
203#ifndef CONFIG_IP_MULTIPLE_TABLES
204
205#define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
206#define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
207
208static inline struct fib_table *fib_get_table(struct net *net, u32 id)
209{
210 struct hlist_node *tb_hlist;
211 struct hlist_head *ptr;
212
213 ptr = id == RT_TABLE_LOCAL ?
214 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
215 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
216
217 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
218
219 return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
220}
221
222static inline struct fib_table *fib_new_table(struct net *net, u32 id)
223{
224 return fib_get_table(net, id);
225}
226
227static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
228 struct fib_result *res, unsigned int flags)
229{
230 struct fib_table *tb;
231 int err = -ENETUNREACH;
232
233 rcu_read_lock();
234
235 tb = fib_get_table(net, RT_TABLE_MAIN);
236 if (tb && !fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF))
237 err = 0;
238
239 rcu_read_unlock();
240
241 return err;
242}
243
244#else /* CONFIG_IP_MULTIPLE_TABLES */
245int __net_init fib4_rules_init(struct net *net);
246void __net_exit fib4_rules_exit(struct net *net);
247
248struct fib_table *fib_new_table(struct net *net, u32 id);
249struct fib_table *fib_get_table(struct net *net, u32 id);
250
251int __fib_lookup(struct net *net, struct flowi4 *flp,
252 struct fib_result *res, unsigned int flags);
253
254static inline int fib_lookup(struct net *net, struct flowi4 *flp,
255 struct fib_result *res, unsigned int flags)
256{
257 struct fib_table *tb;
258 int err;
259
260 flags |= FIB_LOOKUP_NOREF;
261 if (net->ipv4.fib_has_custom_rules)
262 return __fib_lookup(net, flp, res, flags);
263
264 rcu_read_lock();
265
266 res->tclassid = 0;
267
268 for (err = 0; !err; err = -ENETUNREACH) {
269 tb = rcu_dereference_rtnl(net->ipv4.fib_main);
270 if (tb && !fib_table_lookup(tb, flp, res, flags))
271 break;
272
273 tb = rcu_dereference_rtnl(net->ipv4.fib_default);
274 if (tb && !fib_table_lookup(tb, flp, res, flags))
275 break;
276 }
277
278 rcu_read_unlock();
279
280 return err;
281}
282
283#endif /* CONFIG_IP_MULTIPLE_TABLES */
284
285/* Exported by fib_frontend.c */
286extern const struct nla_policy rtm_ipv4_policy[];
287void ip_fib_init(void);
288__be32 fib_compute_spec_dst(struct sk_buff *skb);
289int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
290 u8 tos, int oif, struct net_device *dev,
291 struct in_device *idev, u32 *itag);
292void fib_select_default(const struct flowi4 *flp, struct fib_result *res);
293#ifdef CONFIG_IP_ROUTE_CLASSID
294static inline int fib_num_tclassid_users(struct net *net)
295{
296 return net->ipv4.fib_num_tclassid_users;
297}
298#else
299static inline int fib_num_tclassid_users(struct net *net)
300{
301 return 0;
302}
303#endif
304int fib_unmerge(struct net *net);
305void fib_flush_external(struct net *net);
306
307/* Exported by fib_semantics.c */
308int ip_fib_check_default(__be32 gw, struct net_device *dev);
309int fib_sync_down_dev(struct net_device *dev, unsigned long event);
310int fib_sync_down_addr(struct net *net, __be32 local);
311int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
312void fib_select_multipath(struct fib_result *res);
313
314/* Exported by fib_trie.c */
315void fib_trie_init(void);
316struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
317
318static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
319{
320#ifdef CONFIG_IP_ROUTE_CLASSID
321#ifdef CONFIG_IP_MULTIPLE_TABLES
322 u32 rtag;
323#endif
324 *itag = FIB_RES_NH(*res).nh_tclassid<<16;
325#ifdef CONFIG_IP_MULTIPLE_TABLES
326 rtag = res->tclassid;
327 if (*itag == 0)
328 *itag = (rtag<<16);
329 *itag |= (rtag>>16);
330#endif
331#endif
332}
333
334void free_fib_info(struct fib_info *fi);
335
336static inline void fib_info_put(struct fib_info *fi)
337{
338 if (atomic_dec_and_test(&fi->fib_clntref))
339 free_fib_info(fi);
340}
341
342#ifdef CONFIG_PROC_FS
343int __net_init fib_proc_init(struct net *net);
344void __net_exit fib_proc_exit(struct net *net);
345#else
346static inline int fib_proc_init(struct net *net)
347{
348 return 0;
349}
350static inline void fib_proc_exit(struct net *net)
351{
352}
353#endif
354
355#endif /* _NET_FIB_H */