xref: /openbmc/linux/include/net/ip_fib.h (revision 5104d265)
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 };
63 
64 struct fnhe_hash_bucket {
65 	struct fib_nh_exception __rcu	*chain;
66 };
67 
68 #define FNHE_HASH_SIZE		2048
69 #define FNHE_RECLAIM_DEPTH	5
70 
71 struct fib_nh {
72 	struct net_device	*nh_dev;
73 	struct hlist_node	nh_hash;
74 	struct fib_info		*nh_parent;
75 	unsigned int		nh_flags;
76 	unsigned char		nh_scope;
77 #ifdef CONFIG_IP_ROUTE_MULTIPATH
78 	int			nh_weight;
79 	int			nh_power;
80 #endif
81 #ifdef CONFIG_IP_ROUTE_CLASSID
82 	__u32			nh_tclassid;
83 #endif
84 	int			nh_oif;
85 	__be32			nh_gw;
86 	__be32			nh_saddr;
87 	int			nh_saddr_genid;
88 	struct rtable __rcu * __percpu *nh_pcpu_rth_output;
89 	struct rtable __rcu	*nh_rth_input;
90 	struct fnhe_hash_bucket	*nh_exceptions;
91 };
92 
93 /*
94  * This structure contains data shared by many of routes.
95  */
96 
97 struct fib_info {
98 	struct hlist_node	fib_hash;
99 	struct hlist_node	fib_lhash;
100 	struct net		*fib_net;
101 	int			fib_treeref;
102 	atomic_t		fib_clntref;
103 	unsigned int		fib_flags;
104 	unsigned char		fib_dead;
105 	unsigned char		fib_protocol;
106 	unsigned char		fib_scope;
107 	unsigned char		fib_type;
108 	__be32			fib_prefsrc;
109 	u32			fib_priority;
110 	u32			*fib_metrics;
111 #define fib_mtu fib_metrics[RTAX_MTU-1]
112 #define fib_window fib_metrics[RTAX_WINDOW-1]
113 #define fib_rtt fib_metrics[RTAX_RTT-1]
114 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
115 	int			fib_nhs;
116 #ifdef CONFIG_IP_ROUTE_MULTIPATH
117 	int			fib_power;
118 #endif
119 	struct rcu_head		rcu;
120 	struct fib_nh		fib_nh[0];
121 #define fib_dev		fib_nh[0].nh_dev
122 };
123 
124 
125 #ifdef CONFIG_IP_MULTIPLE_TABLES
126 struct fib_rule;
127 #endif
128 
129 struct fib_table;
130 struct fib_result {
131 	unsigned char	prefixlen;
132 	unsigned char	nh_sel;
133 	unsigned char	type;
134 	unsigned char	scope;
135 	u32		tclassid;
136 	struct fib_info *fi;
137 	struct fib_table *table;
138 	struct list_head *fa_head;
139 };
140 
141 struct fib_result_nl {
142 	__be32		fl_addr;   /* To be looked up*/
143 	u32		fl_mark;
144 	unsigned char	fl_tos;
145 	unsigned char   fl_scope;
146 	unsigned char   tb_id_in;
147 
148 	unsigned char   tb_id;      /* Results */
149 	unsigned char	prefixlen;
150 	unsigned char	nh_sel;
151 	unsigned char	type;
152 	unsigned char	scope;
153 	int             err;
154 };
155 
156 #ifdef CONFIG_IP_ROUTE_MULTIPATH
157 #define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
158 #else /* CONFIG_IP_ROUTE_MULTIPATH */
159 #define FIB_RES_NH(res)		((res).fi->fib_nh[0])
160 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
161 
162 #ifdef CONFIG_IP_MULTIPLE_TABLES
163 #define FIB_TABLE_HASHSZ 256
164 #else
165 #define FIB_TABLE_HASHSZ 2
166 #endif
167 
168 extern __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
169 
170 #define FIB_RES_SADDR(net, res)				\
171 	((FIB_RES_NH(res).nh_saddr_genid ==		\
172 	  atomic_read(&(net)->ipv4.dev_addr_genid)) ?	\
173 	 FIB_RES_NH(res).nh_saddr :			\
174 	 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
175 #define FIB_RES_GW(res)			(FIB_RES_NH(res).nh_gw)
176 #define FIB_RES_DEV(res)		(FIB_RES_NH(res).nh_dev)
177 #define FIB_RES_OIF(res)		(FIB_RES_NH(res).nh_oif)
178 
179 #define FIB_RES_PREFSRC(net, res)	((res).fi->fib_prefsrc ? : \
180 					 FIB_RES_SADDR(net, res))
181 
182 struct fib_table {
183 	struct hlist_node	tb_hlist;
184 	u32			tb_id;
185 	int			tb_default;
186 	int			tb_num_default;
187 	unsigned long		tb_data[0];
188 };
189 
190 extern int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
191 			    struct fib_result *res, int fib_flags);
192 extern int fib_table_insert(struct fib_table *, struct fib_config *);
193 extern int fib_table_delete(struct fib_table *, struct fib_config *);
194 extern int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
195 			  struct netlink_callback *cb);
196 extern int fib_table_flush(struct fib_table *table);
197 extern void fib_free_table(struct fib_table *tb);
198 
199 
200 
201 #ifndef CONFIG_IP_MULTIPLE_TABLES
202 
203 #define TABLE_LOCAL_INDEX	0
204 #define TABLE_MAIN_INDEX	1
205 
206 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
207 {
208 	struct hlist_head *ptr;
209 
210 	ptr = id == RT_TABLE_LOCAL ?
211 		&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
212 		&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
213 	return hlist_entry(ptr->first, struct fib_table, tb_hlist);
214 }
215 
216 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
217 {
218 	return fib_get_table(net, id);
219 }
220 
221 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
222 			     struct fib_result *res)
223 {
224 	struct fib_table *table;
225 
226 	table = fib_get_table(net, RT_TABLE_LOCAL);
227 	if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
228 		return 0;
229 
230 	table = fib_get_table(net, RT_TABLE_MAIN);
231 	if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
232 		return 0;
233 	return -ENETUNREACH;
234 }
235 
236 #else /* CONFIG_IP_MULTIPLE_TABLES */
237 extern int __net_init fib4_rules_init(struct net *net);
238 extern void __net_exit fib4_rules_exit(struct net *net);
239 
240 extern struct fib_table *fib_new_table(struct net *net, u32 id);
241 extern struct fib_table *fib_get_table(struct net *net, u32 id);
242 
243 extern int __fib_lookup(struct net *net, struct flowi4 *flp,
244 			struct fib_result *res);
245 
246 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
247 			     struct fib_result *res)
248 {
249 	if (!net->ipv4.fib_has_custom_rules) {
250 		res->tclassid = 0;
251 		if (net->ipv4.fib_local &&
252 		    !fib_table_lookup(net->ipv4.fib_local, flp, res,
253 				      FIB_LOOKUP_NOREF))
254 			return 0;
255 		if (net->ipv4.fib_main &&
256 		    !fib_table_lookup(net->ipv4.fib_main, flp, res,
257 				      FIB_LOOKUP_NOREF))
258 			return 0;
259 		if (net->ipv4.fib_default &&
260 		    !fib_table_lookup(net->ipv4.fib_default, flp, res,
261 				      FIB_LOOKUP_NOREF))
262 			return 0;
263 		return -ENETUNREACH;
264 	}
265 	return __fib_lookup(net, flp, res);
266 }
267 
268 #endif /* CONFIG_IP_MULTIPLE_TABLES */
269 
270 /* Exported by fib_frontend.c */
271 extern const struct nla_policy rtm_ipv4_policy[];
272 extern void		ip_fib_init(void);
273 extern __be32 fib_compute_spec_dst(struct sk_buff *skb);
274 extern int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
275 			       u8 tos, int oif, struct net_device *dev,
276 			       struct in_device *idev, u32 *itag);
277 extern void fib_select_default(struct fib_result *res);
278 #ifdef CONFIG_IP_ROUTE_CLASSID
279 static inline int fib_num_tclassid_users(struct net *net)
280 {
281 	return net->ipv4.fib_num_tclassid_users;
282 }
283 #else
284 static inline int fib_num_tclassid_users(struct net *net)
285 {
286 	return 0;
287 }
288 #endif
289 
290 /* Exported by fib_semantics.c */
291 extern int ip_fib_check_default(__be32 gw, struct net_device *dev);
292 extern int fib_sync_down_dev(struct net_device *dev, int force);
293 extern int fib_sync_down_addr(struct net *net, __be32 local);
294 extern int fib_sync_up(struct net_device *dev);
295 extern void fib_select_multipath(struct fib_result *res);
296 
297 /* Exported by fib_trie.c */
298 extern void fib_trie_init(void);
299 extern struct fib_table *fib_trie_table(u32 id);
300 
301 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
302 {
303 #ifdef CONFIG_IP_ROUTE_CLASSID
304 #ifdef CONFIG_IP_MULTIPLE_TABLES
305 	u32 rtag;
306 #endif
307 	*itag = FIB_RES_NH(*res).nh_tclassid<<16;
308 #ifdef CONFIG_IP_MULTIPLE_TABLES
309 	rtag = res->tclassid;
310 	if (*itag == 0)
311 		*itag = (rtag<<16);
312 	*itag |= (rtag>>16);
313 #endif
314 #endif
315 }
316 
317 extern void free_fib_info(struct fib_info *fi);
318 
319 static inline void fib_info_put(struct fib_info *fi)
320 {
321 	if (atomic_dec_and_test(&fi->fib_clntref))
322 		free_fib_info(fi);
323 }
324 
325 #ifdef CONFIG_PROC_FS
326 extern int __net_init  fib_proc_init(struct net *net);
327 extern void __net_exit fib_proc_exit(struct net *net);
328 #else
329 static inline int fib_proc_init(struct net *net)
330 {
331 	return 0;
332 }
333 static inline void fib_proc_exit(struct net *net)
334 {
335 }
336 #endif
337 
338 #endif  /* _NET_FIB_H */
339