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
26struct 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
49struct fib_info;
50struct rtable;
51
52struct 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
65struct 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
73struct 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
99struct 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
128struct fib_rule;
129#endif
130
131struct fib_table;
132struct 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
143struct 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
184struct 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
194int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
195		     struct fib_result *res, int fib_flags);
196int fib_table_insert(struct fib_table *, struct fib_config *);
197int fib_table_delete(struct fib_table *, struct fib_config *);
198int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
199		   struct netlink_callback *cb);
200int fib_table_flush(struct fib_table *table);
201struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
202void fib_table_flush_external(struct fib_table *table);
203void 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
210static 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
224static inline struct fib_table *fib_new_table(struct net *net, u32 id)
225{
226	return fib_get_table(net, id);
227}
228
229static 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 */
247int __net_init fib4_rules_init(struct net *net);
248void __net_exit fib4_rules_exit(struct net *net);
249
250struct fib_table *fib_new_table(struct net *net, u32 id);
251struct fib_table *fib_get_table(struct net *net, u32 id);
252
253int __fib_lookup(struct net *net, struct flowi4 *flp, struct fib_result *res);
254
255static 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 */
286extern const struct nla_policy rtm_ipv4_policy[];
287void ip_fib_init(void);
288__be32 fib_compute_spec_dst(struct sk_buff *skb);
289int 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);
292void fib_select_default(struct fib_result *res);
293#ifdef CONFIG_IP_ROUTE_CLASSID
294static inline int fib_num_tclassid_users(struct net *net)
295{
296	return net->ipv4.fib_num_tclassid_users;
297}
298#else
299static inline int fib_num_tclassid_users(struct net *net)
300{
301	return 0;
302}
303#endif
304int fib_unmerge(struct net *net);
305void fib_flush_external(struct net *net);
306
307/* Exported by fib_semantics.c */
308int ip_fib_check_default(__be32 gw, struct net_device *dev);
309int fib_sync_down_dev(struct net_device *dev, int force);
310int fib_sync_down_addr(struct net *net, __be32 local);
311int fib_sync_up(struct net_device *dev);
312void fib_select_multipath(struct fib_result *res);
313
314/* Exported by fib_trie.c */
315void fib_trie_init(void);
316struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
317
318static 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
334void free_fib_info(struct fib_info *fi);
335
336static 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
343int __net_init fib_proc_init(struct net *net);
344void __net_exit fib_proc_exit(struct net *net);
345#else
346static inline int fib_proc_init(struct net *net)
347{
348	return 0;
349}
350static inline void fib_proc_exit(struct net *net)
351{
352}
353#endif
354
355#endif  /* _NET_FIB_H */
356