xref: /openbmc/linux/include/net/ip_fib.h (revision 87c2ce3b)
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 #include <net/flow.h>
21 #include <linux/seq_file.h>
22 
23 /* WARNING: The ordering of these elements must match ordering
24  *          of RTA_* rtnetlink attribute numbers.
25  */
26 struct kern_rta {
27 	void		*rta_dst;
28 	void		*rta_src;
29 	int		*rta_iif;
30 	int		*rta_oif;
31 	void		*rta_gw;
32 	u32		*rta_priority;
33 	void		*rta_prefsrc;
34 	struct rtattr	*rta_mx;
35 	struct rtattr	*rta_mp;
36 	unsigned char	*rta_protoinfo;
37 	u32		*rta_flow;
38 	struct rta_cacheinfo *rta_ci;
39 	struct rta_session *rta_sess;
40 	u32		*rta_mp_alg;
41 };
42 
43 struct fib_info;
44 
45 struct fib_nh {
46 	struct net_device	*nh_dev;
47 	struct hlist_node	nh_hash;
48 	struct fib_info		*nh_parent;
49 	unsigned		nh_flags;
50 	unsigned char		nh_scope;
51 #ifdef CONFIG_IP_ROUTE_MULTIPATH
52 	int			nh_weight;
53 	int			nh_power;
54 #endif
55 #ifdef CONFIG_NET_CLS_ROUTE
56 	__u32			nh_tclassid;
57 #endif
58 	int			nh_oif;
59 	u32			nh_gw;
60 };
61 
62 /*
63  * This structure contains data shared by many of routes.
64  */
65 
66 struct fib_info {
67 	struct hlist_node	fib_hash;
68 	struct hlist_node	fib_lhash;
69 	int			fib_treeref;
70 	atomic_t		fib_clntref;
71 	int			fib_dead;
72 	unsigned		fib_flags;
73 	int			fib_protocol;
74 	u32			fib_prefsrc;
75 	u32			fib_priority;
76 	u32			fib_metrics[RTAX_MAX];
77 #define fib_mtu fib_metrics[RTAX_MTU-1]
78 #define fib_window fib_metrics[RTAX_WINDOW-1]
79 #define fib_rtt fib_metrics[RTAX_RTT-1]
80 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
81 	int			fib_nhs;
82 #ifdef CONFIG_IP_ROUTE_MULTIPATH
83 	int			fib_power;
84 #endif
85 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
86 	u32			fib_mp_alg;
87 #endif
88 	struct fib_nh		fib_nh[0];
89 #define fib_dev		fib_nh[0].nh_dev
90 };
91 
92 
93 #ifdef CONFIG_IP_MULTIPLE_TABLES
94 struct fib_rule;
95 #endif
96 
97 struct fib_result {
98 	unsigned char	prefixlen;
99 	unsigned char	nh_sel;
100 	unsigned char	type;
101 	unsigned char	scope;
102 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
103 	__u32           network;
104 	__u32           netmask;
105 #endif
106 	struct fib_info *fi;
107 #ifdef CONFIG_IP_MULTIPLE_TABLES
108 	struct fib_rule	*r;
109 #endif
110 };
111 
112 struct fib_result_nl {
113 	u32		fl_addr;   /* To be looked up*/
114 	u32		fl_fwmark;
115 	unsigned char	fl_tos;
116 	unsigned char   fl_scope;
117 	unsigned char   tb_id_in;
118 
119 	unsigned char   tb_id;      /* Results */
120 	unsigned char	prefixlen;
121 	unsigned char	nh_sel;
122 	unsigned char	type;
123 	unsigned char	scope;
124 	int             err;
125 };
126 
127 #ifdef CONFIG_IP_ROUTE_MULTIPATH
128 
129 #define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
130 #define FIB_RES_RESET(res)	((res).nh_sel = 0)
131 
132 #else /* CONFIG_IP_ROUTE_MULTIPATH */
133 
134 #define FIB_RES_NH(res)		((res).fi->fib_nh[0])
135 #define FIB_RES_RESET(res)
136 
137 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
138 
139 #define FIB_RES_PREFSRC(res)		((res).fi->fib_prefsrc ? : __fib_res_prefsrc(&res))
140 #define FIB_RES_GW(res)			(FIB_RES_NH(res).nh_gw)
141 #define FIB_RES_DEV(res)		(FIB_RES_NH(res).nh_dev)
142 #define FIB_RES_OIF(res)		(FIB_RES_NH(res).nh_oif)
143 
144 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
145 #define FIB_RES_NETWORK(res)		((res).network)
146 #define FIB_RES_NETMASK(res)	        ((res).netmask)
147 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
148 #define FIB_RES_NETWORK(res)		(0)
149 #define FIB_RES_NETMASK(res)	        (0)
150 #endif /* CONFIG_IP_ROUTE_MULTIPATH_WRANDOM */
151 
152 struct fib_table {
153 	unsigned char	tb_id;
154 	unsigned	tb_stamp;
155 	int		(*tb_lookup)(struct fib_table *tb, const struct flowi *flp, struct fib_result *res);
156 	int		(*tb_insert)(struct fib_table *table, struct rtmsg *r,
157 				     struct kern_rta *rta, struct nlmsghdr *n,
158 				     struct netlink_skb_parms *req);
159 	int		(*tb_delete)(struct fib_table *table, struct rtmsg *r,
160 				     struct kern_rta *rta, struct nlmsghdr *n,
161 				     struct netlink_skb_parms *req);
162 	int		(*tb_dump)(struct fib_table *table, struct sk_buff *skb,
163 				     struct netlink_callback *cb);
164 	int		(*tb_flush)(struct fib_table *table);
165 	void		(*tb_select_default)(struct fib_table *table,
166 					     const struct flowi *flp, struct fib_result *res);
167 
168 	unsigned char	tb_data[0];
169 };
170 
171 #ifndef CONFIG_IP_MULTIPLE_TABLES
172 
173 extern struct fib_table *ip_fib_local_table;
174 extern struct fib_table *ip_fib_main_table;
175 
176 static inline struct fib_table *fib_get_table(int id)
177 {
178 	if (id != RT_TABLE_LOCAL)
179 		return ip_fib_main_table;
180 	return ip_fib_local_table;
181 }
182 
183 static inline struct fib_table *fib_new_table(int id)
184 {
185 	return fib_get_table(id);
186 }
187 
188 static inline int fib_lookup(const struct flowi *flp, struct fib_result *res)
189 {
190 	if (ip_fib_local_table->tb_lookup(ip_fib_local_table, flp, res) &&
191 	    ip_fib_main_table->tb_lookup(ip_fib_main_table, flp, res))
192 		return -ENETUNREACH;
193 	return 0;
194 }
195 
196 static inline void fib_select_default(const struct flowi *flp, struct fib_result *res)
197 {
198 	if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
199 		ip_fib_main_table->tb_select_default(ip_fib_main_table, flp, res);
200 }
201 
202 #else /* CONFIG_IP_MULTIPLE_TABLES */
203 #define ip_fib_local_table (fib_tables[RT_TABLE_LOCAL])
204 #define ip_fib_main_table (fib_tables[RT_TABLE_MAIN])
205 
206 extern struct fib_table * fib_tables[RT_TABLE_MAX+1];
207 extern int fib_lookup(const struct flowi *flp, struct fib_result *res);
208 extern struct fib_table *__fib_new_table(int id);
209 extern void fib_rule_put(struct fib_rule *r);
210 
211 static inline struct fib_table *fib_get_table(int id)
212 {
213 	if (id == 0)
214 		id = RT_TABLE_MAIN;
215 
216 	return fib_tables[id];
217 }
218 
219 static inline struct fib_table *fib_new_table(int id)
220 {
221 	if (id == 0)
222 		id = RT_TABLE_MAIN;
223 
224 	return fib_tables[id] ? : __fib_new_table(id);
225 }
226 
227 extern void fib_select_default(const struct flowi *flp, struct fib_result *res);
228 
229 #endif /* CONFIG_IP_MULTIPLE_TABLES */
230 
231 /* Exported by fib_frontend.c */
232 extern void		ip_fib_init(void);
233 extern int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
234 extern int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
235 extern int inet_rtm_getroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
236 extern int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb);
237 extern int fib_validate_source(u32 src, u32 dst, u8 tos, int oif,
238 			       struct net_device *dev, u32 *spec_dst, u32 *itag);
239 extern void fib_select_multipath(const struct flowi *flp, struct fib_result *res);
240 
241 struct rtentry;
242 
243 /* Exported by fib_semantics.c */
244 extern int ip_fib_check_default(u32 gw, struct net_device *dev);
245 extern int fib_sync_down(u32 local, struct net_device *dev, int force);
246 extern int fib_sync_up(struct net_device *dev);
247 extern int fib_convert_rtentry(int cmd, struct nlmsghdr *nl, struct rtmsg *rtm,
248 			       struct kern_rta *rta, struct rtentry *r);
249 extern u32  __fib_res_prefsrc(struct fib_result *res);
250 
251 /* Exported by fib_hash.c */
252 extern struct fib_table *fib_hash_init(int id);
253 
254 #ifdef CONFIG_IP_MULTIPLE_TABLES
255 /* Exported by fib_rules.c */
256 
257 extern int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
258 extern int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
259 extern int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb);
260 #ifdef CONFIG_NET_CLS_ROUTE
261 extern u32 fib_rules_tclass(struct fib_result *res);
262 #endif
263 extern void fib_rules_init(void);
264 #endif
265 
266 static inline void fib_combine_itag(u32 *itag, struct fib_result *res)
267 {
268 #ifdef CONFIG_NET_CLS_ROUTE
269 #ifdef CONFIG_IP_MULTIPLE_TABLES
270 	u32 rtag;
271 #endif
272 	*itag = FIB_RES_NH(*res).nh_tclassid<<16;
273 #ifdef CONFIG_IP_MULTIPLE_TABLES
274 	rtag = fib_rules_tclass(res);
275 	if (*itag == 0)
276 		*itag = (rtag<<16);
277 	*itag |= (rtag>>16);
278 #endif
279 #endif
280 }
281 
282 extern void free_fib_info(struct fib_info *fi);
283 
284 static inline void fib_info_put(struct fib_info *fi)
285 {
286 	if (atomic_dec_and_test(&fi->fib_clntref))
287 		free_fib_info(fi);
288 }
289 
290 static inline void fib_res_put(struct fib_result *res)
291 {
292 	if (res->fi)
293 		fib_info_put(res->fi);
294 #ifdef CONFIG_IP_MULTIPLE_TABLES
295 	if (res->r)
296 		fib_rule_put(res->r);
297 #endif
298 }
299 
300 #ifdef CONFIG_PROC_FS
301 extern int  fib_proc_init(void);
302 extern void fib_proc_exit(void);
303 #endif
304 
305 #endif  /* _NET_FIB_H */
306