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 <linux/config.h>
20 
21 struct kern_rta
22 {
23 	void		*rta_dst;
24 	void		*rta_src;
25 	int		*rta_iif;
26 	int		*rta_oif;
27 	void		*rta_gw;
28 	u32		*rta_priority;
29 	void		*rta_prefsrc;
30 	struct rtattr	*rta_mx;
31 	struct rtattr	*rta_mp;
32 	unsigned char	*rta_protoinfo;
33 	unsigned char	*rta_flow;
34 	struct rta_cacheinfo *rta_ci;
35 };
36 
37 struct fib_nh
38 {
39 	struct net_device		*nh_dev;
40 	unsigned		nh_flags;
41 	unsigned char		nh_scope;
42 #ifdef CONFIG_IP_ROUTE_MULTIPATH
43 	int			nh_weight;
44 	int			nh_power;
45 #endif
46 #ifdef CONFIG_NET_CLS_ROUTE
47 	__u32			nh_tclassid;
48 #endif
49 	int			nh_oif;
50 	u32			nh_gw;
51 };
52 
53 /*
54  * This structure contains data shared by many of routes.
55  */
56 
57 struct fib_info
58 {
59 	struct fib_info		*fib_next;
60 	struct fib_info		*fib_prev;
61 	int			fib_treeref;
62 	atomic_t		fib_clntref;
63 	int			fib_dead;
64 	unsigned		fib_flags;
65 	int			fib_protocol;
66 	u32			fib_prefsrc;
67 	u32			fib_priority;
68 	unsigned		fib_metrics[RTAX_MAX];
69 #define fib_mtu fib_metrics[RTAX_MTU-1]
70 #define fib_window fib_metrics[RTAX_WINDOW-1]
71 #define fib_rtt fib_metrics[RTAX_RTT-1]
72 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
73 	int			fib_nhs;
74 #ifdef CONFIG_IP_ROUTE_MULTIPATH
75 	int			fib_power;
76 #endif
77 	struct fib_nh		fib_nh[0];
78 #define fib_dev		fib_nh[0].nh_dev
79 };
80 
81 
82 #ifdef CONFIG_IP_MULTIPLE_TABLES
83 struct fib_rule;
84 #endif
85 
86 struct fib_result
87 {
88 	unsigned char	prefixlen;
89 	unsigned char	nh_sel;
90 	unsigned char	type;
91 	unsigned char	scope;
92 	struct fib_info *fi;
93 #ifdef CONFIG_IP_MULTIPLE_TABLES
94 	struct fib_rule	*r;
95 #endif
96 };
97 
98 
99 #ifdef CONFIG_IP_ROUTE_MULTIPATH
100 
101 #define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
102 #define FIB_RES_RESET(res)	((res).nh_sel = 0)
103 
104 #else /* CONFIG_IP_ROUTE_MULTIPATH */
105 
106 #define FIB_RES_NH(res)		((res).fi->fib_nh[0])
107 #define FIB_RES_RESET(res)
108 
109 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
110 
111 #define FIB_RES_PREFSRC(res)		((res).fi->fib_prefsrc ? : __fib_res_prefsrc(&res))
112 #define FIB_RES_GW(res)			(FIB_RES_NH(res).nh_gw)
113 #define FIB_RES_DEV(res)		(FIB_RES_NH(res).nh_dev)
114 #define FIB_RES_OIF(res)		(FIB_RES_NH(res).nh_oif)
115 
116 struct fib_table
117 {
118 	unsigned char	tb_id;
119 	unsigned	tb_stamp;
120 	int		(*tb_lookup)(struct fib_table *tb, const struct rt_key *key, struct fib_result *res);
121 	int		(*tb_insert)(struct fib_table *table, struct rtmsg *r,
122 				     struct kern_rta *rta, struct nlmsghdr *n,
123 				     struct netlink_skb_parms *req);
124 	int		(*tb_delete)(struct fib_table *table, struct rtmsg *r,
125 				     struct kern_rta *rta, struct nlmsghdr *n,
126 				     struct netlink_skb_parms *req);
127 	int		(*tb_dump)(struct fib_table *table, struct sk_buff *skb,
128 				     struct netlink_callback *cb);
129 	int		(*tb_flush)(struct fib_table *table);
130 	int		(*tb_get_info)(struct fib_table *table, char *buf,
131 				       int first, int count);
132 	void		(*tb_select_default)(struct fib_table *table,
133 					     const struct rt_key *key, struct fib_result *res);
134 
135 	unsigned char	tb_data[0];
136 };
137 
138 #ifndef CONFIG_IP_MULTIPLE_TABLES
139 
140 extern struct fib_table *local_table;
141 extern struct fib_table *main_table;
142 
fib_get_table(int id)143 static inline struct fib_table *fib_get_table(int id)
144 {
145 	if (id != RT_TABLE_LOCAL)
146 		return main_table;
147 	return local_table;
148 }
149 
fib_new_table(int id)150 static inline struct fib_table *fib_new_table(int id)
151 {
152 	return fib_get_table(id);
153 }
154 
fib_lookup(const struct rt_key * key,struct fib_result * res)155 static inline int fib_lookup(const struct rt_key *key, struct fib_result *res)
156 {
157 	if (local_table->tb_lookup(local_table, key, res) &&
158 	    main_table->tb_lookup(main_table, key, res))
159 		return -ENETUNREACH;
160 	return 0;
161 }
162 
fib_select_default(const struct rt_key * key,struct fib_result * res)163 static inline void fib_select_default(const struct rt_key *key, struct fib_result *res)
164 {
165 	if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
166 		main_table->tb_select_default(main_table, key, res);
167 }
168 
169 #else /* CONFIG_IP_MULTIPLE_TABLES */
170 #define local_table (fib_tables[RT_TABLE_LOCAL])
171 #define main_table (fib_tables[RT_TABLE_MAIN])
172 
173 extern struct fib_table * fib_tables[RT_TABLE_MAX+1];
174 extern int fib_lookup(const struct rt_key *key, struct fib_result *res);
175 extern struct fib_table *__fib_new_table(int id);
176 extern void fib_rule_put(struct fib_rule *r);
177 
fib_get_table(int id)178 static inline struct fib_table *fib_get_table(int id)
179 {
180 	if (id == 0)
181 		id = RT_TABLE_MAIN;
182 
183 	return fib_tables[id];
184 }
185 
fib_new_table(int id)186 static inline struct fib_table *fib_new_table(int id)
187 {
188 	if (id == 0)
189 		id = RT_TABLE_MAIN;
190 
191 	return fib_tables[id] ? : __fib_new_table(id);
192 }
193 
194 extern void fib_select_default(const struct rt_key *key, struct fib_result *res);
195 
196 #endif /* CONFIG_IP_MULTIPLE_TABLES */
197 
198 /* Exported by fib_frontend.c */
199 extern void		ip_fib_init(void);
200 extern void		fib_flush(void);
201 extern int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
202 extern int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
203 extern int inet_rtm_getroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
204 extern int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb);
205 extern int fib_validate_source(u32 src, u32 dst, u8 tos, int oif,
206 			       struct net_device *dev, u32 *spec_dst, u32 *itag);
207 extern void fib_select_multipath(const struct rt_key *key, struct fib_result *res);
208 
209 /* Exported by fib_semantics.c */
210 extern int 		ip_fib_check_default(u32 gw, struct net_device *dev);
211 extern void		fib_release_info(struct fib_info *);
212 extern int		fib_semantic_match(int type, struct fib_info *,
213 					   const struct rt_key *, struct fib_result*);
214 extern struct fib_info	*fib_create_info(const struct rtmsg *r, struct kern_rta *rta,
215 					 const struct nlmsghdr *, int *err);
216 extern int fib_nh_match(struct rtmsg *r, struct nlmsghdr *, struct kern_rta *rta, struct fib_info *fi);
217 extern int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
218 			 u8 tb_id, u8 type, u8 scope, void *dst, int dst_len, u8 tos,
219 			 struct fib_info *fi);
220 extern int fib_sync_down(u32 local, struct net_device *dev, int force);
221 extern int fib_sync_up(struct net_device *dev);
222 extern int fib_convert_rtentry(int cmd, struct nlmsghdr *nl, struct rtmsg *rtm,
223 			       struct kern_rta *rta, struct rtentry *r);
224 extern void fib_node_get_info(int type, int dead, struct fib_info *fi, u32 prefix, u32 mask, char *buffer);
225 extern u32  __fib_res_prefsrc(struct fib_result *res);
226 
227 /* Exported by fib_hash.c */
228 extern struct fib_table *fib_hash_init(int id);
229 
230 #ifdef CONFIG_IP_MULTIPLE_TABLES
231 /* Exported by fib_rules.c */
232 
233 extern int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
234 extern int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
235 extern int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb);
236 extern u32 fib_rules_map_destination(u32 daddr, struct fib_result *res);
237 #ifdef CONFIG_NET_CLS_ROUTE
238 extern u32 fib_rules_tclass(struct fib_result *res);
239 #endif
240 extern u32 fib_rules_policy(u32 saddr, struct fib_result *res, unsigned *flags);
241 extern void fib_rules_init(void);
242 #endif
243 
fib_combine_itag(u32 * itag,struct fib_result * res)244 static inline void fib_combine_itag(u32 *itag, struct fib_result *res)
245 {
246 #ifdef CONFIG_NET_CLS_ROUTE
247 #ifdef CONFIG_IP_MULTIPLE_TABLES
248 	u32 rtag;
249 #endif
250 	*itag = FIB_RES_NH(*res).nh_tclassid<<16;
251 #ifdef CONFIG_IP_MULTIPLE_TABLES
252 	rtag = fib_rules_tclass(res);
253 	if (*itag == 0)
254 		*itag = (rtag<<16);
255 	*itag |= (rtag>>16);
256 #endif
257 #endif
258 }
259 
260 extern void free_fib_info(struct fib_info *fi);
261 
fib_info_put(struct fib_info * fi)262 static inline void fib_info_put(struct fib_info *fi)
263 {
264 	if (atomic_dec_and_test(&fi->fib_clntref))
265 		free_fib_info(fi);
266 }
267 
fib_res_put(struct fib_result * res)268 static inline void fib_res_put(struct fib_result *res)
269 {
270 	if (res->fi)
271 		fib_info_put(res->fi);
272 #ifdef CONFIG_IP_MULTIPLE_TABLES
273 	if (res->r)
274 		fib_rule_put(res->r);
275 #endif
276 }
277 
278 
279 #endif  /* _NET_FIB_H */
280