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
26 struct 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
49 struct fib_info;
50 struct rtable;
51
52 struct 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 struct rcu_head rcu;
63 };
64
65 struct fnhe_hash_bucket {
66 struct fib_nh_exception __rcu *chain;
67 };
68
69 #define FNHE_HASH_SHIFT 11
70 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT)
71 #define FNHE_RECLAIM_DEPTH 5
72
73 struct fib_nh {
74 struct net_device *nh_dev;
75 struct hlist_node nh_hash;
76 struct fib_info *nh_parent;
77 unsigned int nh_flags;
78 unsigned char nh_scope;
79 #ifdef CONFIG_IP_ROUTE_MULTIPATH
80 int nh_weight;
81 int nh_power;
82 #endif
83 #ifdef CONFIG_IP_ROUTE_CLASSID
84 __u32 nh_tclassid;
85 #endif
86 int nh_oif;
87 __be32 nh_gw;
88 __be32 nh_saddr;
89 int nh_saddr_genid;
90 struct rtable __rcu * __percpu *nh_pcpu_rth_output;
91 struct rtable __rcu *nh_rth_input;
92 struct fnhe_hash_bucket __rcu *nh_exceptions;
93 };
94
95 /*
96 * This structure contains data shared by many of routes.
97 */
98
99 struct fib_info {
100 struct hlist_node fib_hash;
101 struct hlist_node fib_lhash;
102 struct net *fib_net;
103 int fib_treeref;
104 atomic_t fib_clntref;
105 unsigned int fib_flags;
106 unsigned char fib_dead;
107 unsigned char fib_protocol;
108 unsigned char fib_scope;
109 unsigned char fib_type;
110 __be32 fib_prefsrc;
111 u32 fib_priority;
112 u32 *fib_metrics;
113 #define fib_mtu fib_metrics[RTAX_MTU-1]
114 #define fib_window fib_metrics[RTAX_WINDOW-1]
115 #define fib_rtt fib_metrics[RTAX_RTT-1]
116 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
117 int fib_nhs;
118 #ifdef CONFIG_IP_ROUTE_MULTIPATH
119 int fib_power;
120 #endif
121 struct rcu_head rcu;
122 struct fib_nh fib_nh[0];
123 #define fib_dev fib_nh[0].nh_dev
124 };
125
126
127 #ifdef CONFIG_IP_MULTIPLE_TABLES
128 struct fib_rule;
129 #endif
130
131 struct fib_table;
132 struct fib_result {
133 unsigned char prefixlen;
134 unsigned char nh_sel;
135 unsigned char type;
136 unsigned char scope;
137 u32 tclassid;
138 struct fib_info *fi;
139 struct fib_table *table;
140 struct hlist_head *fa_head;
141 };
142
143 struct fib_result_nl {
144 __be32 fl_addr; /* To be looked up*/
145 u32 fl_mark;
146 unsigned char fl_tos;
147 unsigned char fl_scope;
148 unsigned char tb_id_in;
149
150 unsigned char tb_id; /* Results */
151 unsigned char prefixlen;
152 unsigned char nh_sel;
153 unsigned char type;
154 unsigned char scope;
155 int err;
156 };
157
158 #ifdef CONFIG_IP_ROUTE_MULTIPATH
159 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel])
160 #else /* CONFIG_IP_ROUTE_MULTIPATH */
161 #define FIB_RES_NH(res) ((res).fi->fib_nh[0])
162 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
163
164 #ifdef CONFIG_IP_MULTIPLE_TABLES
165 #define FIB_TABLE_HASHSZ 256
166 #else
167 #define FIB_TABLE_HASHSZ 2
168 #endif
169
170 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
171
172 #define FIB_RES_SADDR(net, res) \
173 ((FIB_RES_NH(res).nh_saddr_genid == \
174 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \
175 FIB_RES_NH(res).nh_saddr : \
176 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
177 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw)
178 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev)
179 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif)
180
181 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \
182 FIB_RES_SADDR(net, res))
183
184 struct fib_table {
185 struct hlist_node tb_hlist;
186 u32 tb_id;
187 int tb_default;
188 int tb_num_default;
189 struct rcu_head rcu;
190 unsigned long *tb_data;
191 unsigned long __data[0];
192 };
193
194 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
195 struct fib_result *res, int fib_flags);
196 int fib_table_insert(struct fib_table *, struct fib_config *);
197 int fib_table_delete(struct fib_table *, struct fib_config *);
198 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
199 struct netlink_callback *cb);
200 int fib_table_flush(struct fib_table *table);
201 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
202 void fib_table_flush_external(struct fib_table *table);
203 void fib_free_table(struct fib_table *tb);
204
205 #ifndef CONFIG_IP_MULTIPLE_TABLES
206
207 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
208 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
209
fib_get_table(struct net * net,u32 id)210 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
211 {
212 struct hlist_node *tb_hlist;
213 struct hlist_head *ptr;
214
215 ptr = id == RT_TABLE_LOCAL ?
216 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
217 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
218
219 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
220
221 return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
222 }
223
fib_new_table(struct net * net,u32 id)224 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
225 {
226 return fib_get_table(net, id);
227 }
228
fib_lookup(struct net * net,const struct flowi4 * flp,struct fib_result * res)229 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
230 struct fib_result *res)
231 {
232 struct fib_table *tb;
233 int err = -ENETUNREACH;
234
235 rcu_read_lock();
236
237 tb = fib_get_table(net, RT_TABLE_MAIN);
238 if (tb && !fib_table_lookup(tb, flp, res, FIB_LOOKUP_NOREF))
239 err = 0;
240
241 rcu_read_unlock();
242
243 return err;
244 }
245
246 #else /* CONFIG_IP_MULTIPLE_TABLES */
247 int __net_init fib4_rules_init(struct net *net);
248 void __net_exit fib4_rules_exit(struct net *net);
249
250 struct fib_table *fib_new_table(struct net *net, u32 id);
251 struct fib_table *fib_get_table(struct net *net, u32 id);
252
253 int __fib_lookup(struct net *net, struct flowi4 *flp, struct fib_result *res);
254
fib_lookup(struct net * net,struct flowi4 * flp,struct fib_result * res)255 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
256 struct fib_result *res)
257 {
258 struct fib_table *tb;
259 int err;
260
261 if (net->ipv4.fib_has_custom_rules)
262 return __fib_lookup(net, flp, res);
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, FIB_LOOKUP_NOREF))
271 break;
272
273 tb = rcu_dereference_rtnl(net->ipv4.fib_default);
274 if (tb && !fib_table_lookup(tb, flp, res, FIB_LOOKUP_NOREF))
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 */
286 extern const struct nla_policy rtm_ipv4_policy[];
287 void ip_fib_init(void);
288 __be32 fib_compute_spec_dst(struct sk_buff *skb);
289 int 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);
292 void fib_select_default(struct fib_result *res);
293 #ifdef CONFIG_IP_ROUTE_CLASSID
fib_num_tclassid_users(struct net * net)294 static inline int fib_num_tclassid_users(struct net *net)
295 {
296 return net->ipv4.fib_num_tclassid_users;
297 }
298 #else
fib_num_tclassid_users(struct net * net)299 static inline int fib_num_tclassid_users(struct net *net)
300 {
301 return 0;
302 }
303 #endif
304 int fib_unmerge(struct net *net);
305 void fib_flush_external(struct net *net);
306
307 /* Exported by fib_semantics.c */
308 int ip_fib_check_default(__be32 gw, struct net_device *dev);
309 int fib_sync_down_dev(struct net_device *dev, int force);
310 int fib_sync_down_addr(struct net *net, __be32 local);
311 int fib_sync_up(struct net_device *dev);
312 void fib_select_multipath(struct fib_result *res);
313
314 /* Exported by fib_trie.c */
315 void fib_trie_init(void);
316 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
317
fib_combine_itag(u32 * itag,const struct fib_result * res)318 static 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
334 void free_fib_info(struct fib_info *fi);
335
fib_info_put(struct fib_info * fi)336 static 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
343 int __net_init fib_proc_init(struct net *net);
344 void __net_exit fib_proc_exit(struct net *net);
345 #else
fib_proc_init(struct net * net)346 static inline int fib_proc_init(struct net *net)
347 {
348 return 0;
349 }
fib_proc_exit(struct net * net)350 static inline void fib_proc_exit(struct net *net)
351 {
352 }
353 #endif
354
355 #endif /* _NET_FIB_H */
356