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 __be32 fnhe_daddr;
55 u32 fnhe_pmtu;
56 __be32 fnhe_gw;
57 unsigned long fnhe_expires;
58 struct rtable __rcu *fnhe_rth;
59 unsigned long fnhe_stamp;
60 };
61
62 struct fnhe_hash_bucket {
63 struct fib_nh_exception __rcu *chain;
64 };
65
66 #define FNHE_HASH_SIZE 2048
67 #define FNHE_RECLAIM_DEPTH 5
68
69 struct fib_nh {
70 struct net_device *nh_dev;
71 struct hlist_node nh_hash;
72 struct fib_info *nh_parent;
73 unsigned int nh_flags;
74 unsigned char nh_scope;
75 #ifdef CONFIG_IP_ROUTE_MULTIPATH
76 int nh_weight;
77 int nh_power;
78 #endif
79 #ifdef CONFIG_IP_ROUTE_CLASSID
80 __u32 nh_tclassid;
81 #endif
82 int nh_oif;
83 __be32 nh_gw;
84 __be32 nh_saddr;
85 int nh_saddr_genid;
86 struct rtable __rcu * __percpu *nh_pcpu_rth_output;
87 struct rtable __rcu *nh_rth_input;
88 struct fnhe_hash_bucket *nh_exceptions;
89 };
90
91 /*
92 * This structure contains data shared by many of routes.
93 */
94
95 struct fib_info {
96 struct hlist_node fib_hash;
97 struct hlist_node fib_lhash;
98 struct net *fib_net;
99 int fib_treeref;
100 atomic_t fib_clntref;
101 unsigned int fib_flags;
102 unsigned char fib_dead;
103 unsigned char fib_protocol;
104 unsigned char fib_scope;
105 unsigned char fib_type;
106 __be32 fib_prefsrc;
107 u32 fib_priority;
108 u32 *fib_metrics;
109 #define fib_mtu fib_metrics[RTAX_MTU-1]
110 #define fib_window fib_metrics[RTAX_WINDOW-1]
111 #define fib_rtt fib_metrics[RTAX_RTT-1]
112 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
113 int fib_nhs;
114 #ifdef CONFIG_IP_ROUTE_MULTIPATH
115 int fib_power;
116 #endif
117 struct rcu_head rcu;
118 struct fib_nh fib_nh[0];
119 #define fib_dev fib_nh[0].nh_dev
120 };
121
122
123 #ifdef CONFIG_IP_MULTIPLE_TABLES
124 struct fib_rule;
125 #endif
126
127 struct fib_table;
128 struct fib_result {
129 unsigned char prefixlen;
130 unsigned char nh_sel;
131 unsigned char type;
132 unsigned char scope;
133 u32 tclassid;
134 struct fib_info *fi;
135 struct fib_table *table;
136 struct list_head *fa_head;
137 };
138
139 struct fib_result_nl {
140 __be32 fl_addr; /* To be looked up*/
141 u32 fl_mark;
142 unsigned char fl_tos;
143 unsigned char fl_scope;
144 unsigned char tb_id_in;
145
146 unsigned char tb_id; /* Results */
147 unsigned char prefixlen;
148 unsigned char nh_sel;
149 unsigned char type;
150 unsigned char scope;
151 int err;
152 };
153
154 #ifdef CONFIG_IP_ROUTE_MULTIPATH
155 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel])
156 #else /* CONFIG_IP_ROUTE_MULTIPATH */
157 #define FIB_RES_NH(res) ((res).fi->fib_nh[0])
158 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
159
160 #ifdef CONFIG_IP_MULTIPLE_TABLES
161 #define FIB_TABLE_HASHSZ 256
162 #else
163 #define FIB_TABLE_HASHSZ 2
164 #endif
165
166 extern __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
167
168 #define FIB_RES_SADDR(net, res) \
169 ((FIB_RES_NH(res).nh_saddr_genid == \
170 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \
171 FIB_RES_NH(res).nh_saddr : \
172 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
173 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw)
174 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev)
175 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif)
176
177 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \
178 FIB_RES_SADDR(net, res))
179
180 struct fib_table {
181 struct hlist_node tb_hlist;
182 u32 tb_id;
183 int tb_default;
184 int tb_num_default;
185 unsigned long tb_data[0];
186 };
187
188 extern int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
189 struct fib_result *res, int fib_flags);
190 extern int fib_table_insert(struct fib_table *, struct fib_config *);
191 extern int fib_table_delete(struct fib_table *, struct fib_config *);
192 extern int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
193 struct netlink_callback *cb);
194 extern int fib_table_flush(struct fib_table *table);
195 extern void fib_free_table(struct fib_table *tb);
196
197
198
199 #ifndef CONFIG_IP_MULTIPLE_TABLES
200
201 #define TABLE_LOCAL_INDEX 0
202 #define TABLE_MAIN_INDEX 1
203
fib_get_table(struct net * net,u32 id)204 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
205 {
206 struct hlist_head *ptr;
207
208 ptr = id == RT_TABLE_LOCAL ?
209 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
210 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
211 return hlist_entry(ptr->first, struct fib_table, tb_hlist);
212 }
213
fib_new_table(struct net * net,u32 id)214 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
215 {
216 return fib_get_table(net, id);
217 }
218
fib_lookup(struct net * net,const struct flowi4 * flp,struct fib_result * res)219 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
220 struct fib_result *res)
221 {
222 struct fib_table *table;
223
224 table = fib_get_table(net, RT_TABLE_LOCAL);
225 if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
226 return 0;
227
228 table = fib_get_table(net, RT_TABLE_MAIN);
229 if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
230 return 0;
231 return -ENETUNREACH;
232 }
233
234 #else /* CONFIG_IP_MULTIPLE_TABLES */
235 extern int __net_init fib4_rules_init(struct net *net);
236 extern void __net_exit fib4_rules_exit(struct net *net);
237
238 extern struct fib_table *fib_new_table(struct net *net, u32 id);
239 extern struct fib_table *fib_get_table(struct net *net, u32 id);
240
241 extern int __fib_lookup(struct net *net, struct flowi4 *flp,
242 struct fib_result *res);
243
fib_lookup(struct net * net,struct flowi4 * flp,struct fib_result * res)244 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
245 struct fib_result *res)
246 {
247 if (!net->ipv4.fib_has_custom_rules) {
248 res->tclassid = 0;
249 if (net->ipv4.fib_local &&
250 !fib_table_lookup(net->ipv4.fib_local, flp, res,
251 FIB_LOOKUP_NOREF))
252 return 0;
253 if (net->ipv4.fib_main &&
254 !fib_table_lookup(net->ipv4.fib_main, flp, res,
255 FIB_LOOKUP_NOREF))
256 return 0;
257 if (net->ipv4.fib_default &&
258 !fib_table_lookup(net->ipv4.fib_default, flp, res,
259 FIB_LOOKUP_NOREF))
260 return 0;
261 return -ENETUNREACH;
262 }
263 return __fib_lookup(net, flp, res);
264 }
265
266 #endif /* CONFIG_IP_MULTIPLE_TABLES */
267
268 /* Exported by fib_frontend.c */
269 extern const struct nla_policy rtm_ipv4_policy[];
270 extern void ip_fib_init(void);
271 extern __be32 fib_compute_spec_dst(struct sk_buff *skb);
272 extern int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
273 u8 tos, int oif, struct net_device *dev,
274 struct in_device *idev, u32 *itag);
275 extern void fib_select_default(struct fib_result *res);
276 #ifdef CONFIG_IP_ROUTE_CLASSID
fib_num_tclassid_users(struct net * net)277 static inline int fib_num_tclassid_users(struct net *net)
278 {
279 return net->ipv4.fib_num_tclassid_users;
280 }
281 #else
fib_num_tclassid_users(struct net * net)282 static inline int fib_num_tclassid_users(struct net *net)
283 {
284 return 0;
285 }
286 #endif
287
288 /* Exported by fib_semantics.c */
289 extern int ip_fib_check_default(__be32 gw, struct net_device *dev);
290 extern int fib_sync_down_dev(struct net_device *dev, int force);
291 extern int fib_sync_down_addr(struct net *net, __be32 local);
292 extern void fib_update_nh_saddrs(struct net_device *dev);
293 extern int fib_sync_up(struct net_device *dev);
294 extern void fib_select_multipath(struct fib_result *res);
295
296 /* Exported by fib_trie.c */
297 extern void fib_trie_init(void);
298 extern struct fib_table *fib_trie_table(u32 id);
299
fib_combine_itag(u32 * itag,const struct fib_result * res)300 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
301 {
302 #ifdef CONFIG_IP_ROUTE_CLASSID
303 #ifdef CONFIG_IP_MULTIPLE_TABLES
304 u32 rtag;
305 #endif
306 *itag = FIB_RES_NH(*res).nh_tclassid<<16;
307 #ifdef CONFIG_IP_MULTIPLE_TABLES
308 rtag = res->tclassid;
309 if (*itag == 0)
310 *itag = (rtag<<16);
311 *itag |= (rtag>>16);
312 #endif
313 #endif
314 }
315
316 extern void free_fib_info(struct fib_info *fi);
317
fib_info_put(struct fib_info * fi)318 static inline void fib_info_put(struct fib_info *fi)
319 {
320 if (atomic_dec_and_test(&fi->fib_clntref))
321 free_fib_info(fi);
322 }
323
324 #ifdef CONFIG_PROC_FS
325 extern int __net_init fib_proc_init(struct net *net);
326 extern void __net_exit fib_proc_exit(struct net *net);
327 #else
fib_proc_init(struct net * net)328 static inline int fib_proc_init(struct net *net)
329 {
330 return 0;
331 }
fib_proc_exit(struct net * net)332 static inline void fib_proc_exit(struct net *net)
333 {
334 }
335 #endif
336
337 #endif /* _NET_FIB_H */
338