1 /*
2  *	Linux INET6 implementation
3  *
4  *	Authors:
5  *	Pedro Roque		<roque@di.fc.ul.pt>
6  *
7  *	This program is free software; you can redistribute it and/or
8  *      modify it under the terms of the GNU General Public License
9  *      as published by the Free Software Foundation; either version
10  *      2 of the License, or (at your option) any later version.
11  */
12 
13 #ifndef _IP6_FIB_H
14 #define _IP6_FIB_H
15 
16 #ifdef __KERNEL__
17 
18 #include <linux/ipv6_route.h>
19 #include <linux/rtnetlink.h>
20 #include <linux/spinlock.h>
21 #include <net/dst.h>
22 #include <net/flow.h>
23 #include <net/netlink.h>
24 #include <net/inetpeer.h>
25 
26 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
27 #define FIB6_TABLE_HASHSZ 256
28 #else
29 #define FIB6_TABLE_HASHSZ 1
30 #endif
31 
32 struct rt6_info;
33 
34 struct fib6_config {
35 	u32		fc_table;
36 	u32		fc_metric;
37 	int		fc_dst_len;
38 	int		fc_src_len;
39 	int		fc_ifindex;
40 	u32		fc_flags;
41 	u32		fc_protocol;
42 
43 	struct in6_addr	fc_dst;
44 	struct in6_addr	fc_src;
45 	struct in6_addr	fc_gateway;
46 
47 	unsigned long	fc_expires;
48 	struct nlattr	*fc_mx;
49 	int		fc_mx_len;
50 
51 	struct nl_info	fc_nlinfo;
52 };
53 
54 struct fib6_node {
55 	struct fib6_node	*parent;
56 	struct fib6_node	*left;
57 	struct fib6_node	*right;
58 #ifdef CONFIG_IPV6_SUBTREES
59 	struct fib6_node	*subtree;
60 #endif
61 	struct rt6_info		*leaf;
62 
63 	__u16			fn_bit;		/* bit key */
64 	__u16			fn_flags;
65 	__u32			fn_sernum;
66 	struct rt6_info		*rr_ptr;
67 };
68 
69 #ifndef CONFIG_IPV6_SUBTREES
70 #define FIB6_SUBTREE(fn)	NULL
71 #else
72 #define FIB6_SUBTREE(fn)	((fn)->subtree)
73 #endif
74 
75 /*
76  *	routing information
77  *
78  */
79 
80 struct rt6key {
81 	struct in6_addr	addr;
82 	int		plen;
83 };
84 
85 struct fib6_table;
86 
87 struct rt6_info {
88 	struct dst_entry		dst;
89 
90 #define rt6i_dev			dst.dev
91 #define rt6i_nexthop			dst.neighbour
92 #define rt6i_expires			dst.expires
93 
94 	/*
95 	 * Tail elements of dst_entry (__refcnt etc.)
96 	 * and these elements (rarely used in hot path) are in
97 	 * the same cache line.
98 	 */
99 	struct fib6_table		*rt6i_table;
100 	struct fib6_node		*rt6i_node;
101 
102 	struct in6_addr			rt6i_gateway;
103 
104 	atomic_t			rt6i_ref;
105 
106 	/* These are in a separate cache line. */
107 	struct rt6key			rt6i_dst ____cacheline_aligned_in_smp;
108 	u32				rt6i_flags;
109 	struct rt6key			rt6i_src;
110 	u32				rt6i_metric;
111 	u32				rt6i_peer_genid;
112 
113 	struct inet6_dev		*rt6i_idev;
114 	struct inet_peer		*rt6i_peer;
115 
116 #ifdef CONFIG_XFRM
117 	u32				rt6i_flow_cache_genid;
118 #endif
119 	/* more non-fragment space at head required */
120 	unsigned short			rt6i_nfheader_len;
121 
122 	u8				rt6i_protocol;
123 };
124 
ip6_dst_idev(struct dst_entry * dst)125 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
126 {
127 	return ((struct rt6_info *)dst)->rt6i_idev;
128 }
129 
130 struct fib6_walker_t {
131 	struct list_head lh;
132 	struct fib6_node *root, *node;
133 	struct rt6_info *leaf;
134 	unsigned char state;
135 	unsigned char prune;
136 	unsigned int skip;
137 	unsigned int count;
138 	int (*func)(struct fib6_walker_t *);
139 	void *args;
140 };
141 
142 struct rt6_statistics {
143 	__u32		fib_nodes;
144 	__u32		fib_route_nodes;
145 	__u32		fib_rt_alloc;		/* permanent routes	*/
146 	__u32		fib_rt_entries;		/* rt entries in table	*/
147 	__u32		fib_rt_cache;		/* cache routes		*/
148 	__u32		fib_discarded_routes;
149 };
150 
151 #define RTN_TL_ROOT	0x0001
152 #define RTN_ROOT	0x0002		/* tree root node		*/
153 #define RTN_RTINFO	0x0004		/* node with valid routing info	*/
154 
155 /*
156  *	priority levels (or metrics)
157  *
158  */
159 
160 
161 struct fib6_table {
162 	struct hlist_node	tb6_hlist;
163 	u32			tb6_id;
164 	rwlock_t		tb6_lock;
165 	struct fib6_node	tb6_root;
166 };
167 
168 #define RT6_TABLE_UNSPEC	RT_TABLE_UNSPEC
169 #define RT6_TABLE_MAIN		RT_TABLE_MAIN
170 #define RT6_TABLE_DFLT		RT6_TABLE_MAIN
171 #define RT6_TABLE_INFO		RT6_TABLE_MAIN
172 #define RT6_TABLE_PREFIX	RT6_TABLE_MAIN
173 
174 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
175 #define FIB6_TABLE_MIN		1
176 #define FIB6_TABLE_MAX		RT_TABLE_MAX
177 #define RT6_TABLE_LOCAL		RT_TABLE_LOCAL
178 #else
179 #define FIB6_TABLE_MIN		RT_TABLE_MAIN
180 #define FIB6_TABLE_MAX		FIB6_TABLE_MIN
181 #define RT6_TABLE_LOCAL		RT6_TABLE_MAIN
182 #endif
183 
184 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
185 					 struct fib6_table *,
186 					 struct flowi6 *, int);
187 
188 /*
189  *	exported functions
190  */
191 
192 extern struct fib6_table        *fib6_get_table(struct net *net, u32 id);
193 extern struct fib6_table        *fib6_new_table(struct net *net, u32 id);
194 extern struct dst_entry         *fib6_rule_lookup(struct net *net,
195 						  struct flowi6 *fl6, int flags,
196 						  pol_lookup_t lookup);
197 
198 extern struct fib6_node		*fib6_lookup(struct fib6_node *root,
199 					     struct in6_addr *daddr,
200 					     struct in6_addr *saddr);
201 
202 struct fib6_node		*fib6_locate(struct fib6_node *root,
203 					     struct in6_addr *daddr, int dst_len,
204 					     struct in6_addr *saddr, int src_len);
205 
206 extern void			fib6_clean_all(struct net *net,
207 					       int (*func)(struct rt6_info *, void *arg),
208 					       int prune, void *arg);
209 
210 extern int			fib6_add(struct fib6_node *root,
211 					 struct rt6_info *rt,
212 					 struct nl_info *info);
213 
214 extern int			fib6_del(struct rt6_info *rt,
215 					 struct nl_info *info);
216 
217 extern void			inet6_rt_notify(int event, struct rt6_info *rt,
218 						struct nl_info *info);
219 
220 extern void			fib6_run_gc(unsigned long expires,
221 					    struct net *net);
222 
223 extern void			fib6_gc_cleanup(void);
224 
225 extern int			fib6_init(void);
226 
227 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
228 extern int			fib6_rules_init(void);
229 extern void			fib6_rules_cleanup(void);
230 #else
fib6_rules_init(void)231 static inline int               fib6_rules_init(void)
232 {
233 	return 0;
234 }
fib6_rules_cleanup(void)235 static inline void              fib6_rules_cleanup(void)
236 {
237 	return ;
238 }
239 #endif
240 #endif
241 #endif
242