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 #include <linux/ipv6_route.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/spinlock.h>
19 #include <net/dst.h>
20 #include <net/flow.h>
21 #include <net/netlink.h>
22 #include <net/inetpeer.h>
23 
24 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
25 #define FIB6_TABLE_HASHSZ 256
26 #else
27 #define FIB6_TABLE_HASHSZ 1
28 #endif
29 
30 struct rt6_info;
31 
32 struct fib6_config {
33 	u32		fc_table;
34 	u32		fc_metric;
35 	int		fc_dst_len;
36 	int		fc_src_len;
37 	int		fc_ifindex;
38 	u32		fc_flags;
39 	u32		fc_protocol;
40 
41 	struct in6_addr	fc_dst;
42 	struct in6_addr	fc_src;
43 	struct in6_addr	fc_prefsrc;
44 	struct in6_addr	fc_gateway;
45 
46 	unsigned long	fc_expires;
47 	struct nlattr	*fc_mx;
48 	int		fc_mx_len;
49 
50 	struct nl_info	fc_nlinfo;
51 };
52 
53 struct fib6_node {
54 	struct fib6_node	*parent;
55 	struct fib6_node	*left;
56 	struct fib6_node	*right;
57 #ifdef CONFIG_IPV6_SUBTREES
58 	struct fib6_node	*subtree;
59 #endif
60 	struct rt6_info		*leaf;
61 
62 	__u16			fn_bit;		/* bit key */
63 	__u16			fn_flags;
64 	__u32			fn_sernum;
65 	struct rt6_info		*rr_ptr;
66 };
67 
68 #ifndef CONFIG_IPV6_SUBTREES
69 #define FIB6_SUBTREE(fn)	NULL
70 #else
71 #define FIB6_SUBTREE(fn)	((fn)->subtree)
72 #endif
73 
74 /*
75  *	routing information
76  *
77  */
78 
79 struct rt6key {
80 	struct in6_addr	addr;
81 	int		plen;
82 };
83 
84 struct fib6_table;
85 
86 struct rt6_info {
87 	struct dst_entry		dst;
88 
89 	/*
90 	 * Tail elements of dst_entry (__refcnt etc.)
91 	 * and these elements (rarely used in hot path) are in
92 	 * the same cache line.
93 	 */
94 	struct fib6_table		*rt6i_table;
95 	struct fib6_node		*rt6i_node;
96 
97 	struct in6_addr			rt6i_gateway;
98 
99 	atomic_t			rt6i_ref;
100 
101 	/* These are in a separate cache line. */
102 	struct rt6key			rt6i_dst ____cacheline_aligned_in_smp;
103 	u32				rt6i_flags;
104 	struct rt6key			rt6i_src;
105 	struct rt6key			rt6i_prefsrc;
106 	u32				rt6i_metric;
107 	u32				rt6i_peer_genid;
108 
109 	struct inet6_dev		*rt6i_idev;
110 	struct inet_peer		*rt6i_peer;
111 
112 #ifdef CONFIG_XFRM
113 	u32				rt6i_flow_cache_genid;
114 #endif
115 	/* more non-fragment space at head required */
116 	unsigned short			rt6i_nfheader_len;
117 
118 	u8				rt6i_protocol;
119 };
120 
ip6_dst_idev(struct dst_entry * dst)121 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
122 {
123 	return ((struct rt6_info *)dst)->rt6i_idev;
124 }
125 
rt6_clean_expires(struct rt6_info * rt)126 static inline void rt6_clean_expires(struct rt6_info *rt)
127 {
128 	if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from)
129 		dst_release(rt->dst.from);
130 
131 	rt->rt6i_flags &= ~RTF_EXPIRES;
132 	rt->dst.from = NULL;
133 }
134 
rt6_set_expires(struct rt6_info * rt,unsigned long expires)135 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
136 {
137 	if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from)
138 		dst_release(rt->dst.from);
139 
140 	rt->rt6i_flags |= RTF_EXPIRES;
141 	rt->dst.expires = expires;
142 }
143 
rt6_update_expires(struct rt6_info * rt,int timeout)144 static inline void rt6_update_expires(struct rt6_info *rt, int timeout)
145 {
146 	if (!(rt->rt6i_flags & RTF_EXPIRES)) {
147 		if (rt->dst.from)
148 			dst_release(rt->dst.from);
149 		/* dst_set_expires relies on expires == 0
150 		 * if it has not been set previously.
151 		 */
152 		rt->dst.expires = 0;
153 	}
154 
155 	dst_set_expires(&rt->dst, timeout);
156 	rt->rt6i_flags |= RTF_EXPIRES;
157 }
158 
rt6_set_from(struct rt6_info * rt,struct rt6_info * from)159 static inline void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)
160 {
161 	struct dst_entry *new = (struct dst_entry *) from;
162 
163 	if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from) {
164 		if (new == rt->dst.from)
165 			return;
166 		dst_release(rt->dst.from);
167 	}
168 
169 	rt->rt6i_flags &= ~RTF_EXPIRES;
170 	rt->dst.from = new;
171 	dst_hold(new);
172 }
173 
174 struct fib6_walker_t {
175 	struct list_head lh;
176 	struct fib6_node *root, *node;
177 	struct rt6_info *leaf;
178 	unsigned char state;
179 	unsigned char prune;
180 	unsigned int skip;
181 	unsigned int count;
182 	int (*func)(struct fib6_walker_t *);
183 	void *args;
184 };
185 
186 struct rt6_statistics {
187 	__u32		fib_nodes;
188 	__u32		fib_route_nodes;
189 	__u32		fib_rt_alloc;		/* permanent routes	*/
190 	__u32		fib_rt_entries;		/* rt entries in table	*/
191 	__u32		fib_rt_cache;		/* cache routes		*/
192 	__u32		fib_discarded_routes;
193 };
194 
195 #define RTN_TL_ROOT	0x0001
196 #define RTN_ROOT	0x0002		/* tree root node		*/
197 #define RTN_RTINFO	0x0004		/* node with valid routing info	*/
198 
199 /*
200  *	priority levels (or metrics)
201  *
202  */
203 
204 
205 struct fib6_table {
206 	struct hlist_node	tb6_hlist;
207 	u32			tb6_id;
208 	rwlock_t		tb6_lock;
209 	struct fib6_node	tb6_root;
210 };
211 
212 #define RT6_TABLE_UNSPEC	RT_TABLE_UNSPEC
213 #define RT6_TABLE_MAIN		RT_TABLE_MAIN
214 #define RT6_TABLE_DFLT		RT6_TABLE_MAIN
215 #define RT6_TABLE_INFO		RT6_TABLE_MAIN
216 #define RT6_TABLE_PREFIX	RT6_TABLE_MAIN
217 
218 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
219 #define FIB6_TABLE_MIN		1
220 #define FIB6_TABLE_MAX		RT_TABLE_MAX
221 #define RT6_TABLE_LOCAL		RT_TABLE_LOCAL
222 #else
223 #define FIB6_TABLE_MIN		RT_TABLE_MAIN
224 #define FIB6_TABLE_MAX		FIB6_TABLE_MIN
225 #define RT6_TABLE_LOCAL		RT6_TABLE_MAIN
226 #endif
227 
228 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
229 					 struct fib6_table *,
230 					 struct flowi6 *, int);
231 
232 /*
233  *	exported functions
234  */
235 
236 extern struct fib6_table        *fib6_get_table(struct net *net, u32 id);
237 extern struct fib6_table        *fib6_new_table(struct net *net, u32 id);
238 extern struct dst_entry         *fib6_rule_lookup(struct net *net,
239 						  struct flowi6 *fl6, int flags,
240 						  pol_lookup_t lookup);
241 
242 extern struct fib6_node		*fib6_lookup(struct fib6_node *root,
243 					     const struct in6_addr *daddr,
244 					     const struct in6_addr *saddr);
245 
246 struct fib6_node		*fib6_locate(struct fib6_node *root,
247 					     const struct in6_addr *daddr, int dst_len,
248 					     const struct in6_addr *saddr, int src_len);
249 
250 extern void			fib6_clean_all_ro(struct net *net,
251 					       int (*func)(struct rt6_info *, void *arg),
252 					       int prune, void *arg);
253 
254 extern void			fib6_clean_all(struct net *net,
255 					       int (*func)(struct rt6_info *, void *arg),
256 					       int prune, void *arg);
257 
258 extern int			fib6_add(struct fib6_node *root,
259 					 struct rt6_info *rt,
260 					 struct nl_info *info);
261 
262 extern int			fib6_del(struct rt6_info *rt,
263 					 struct nl_info *info);
264 
265 extern void			inet6_rt_notify(int event, struct rt6_info *rt,
266 						struct nl_info *info);
267 
268 extern void			fib6_run_gc(unsigned long expires,
269 					    struct net *net);
270 
271 extern void			fib6_gc_cleanup(void);
272 
273 extern int			fib6_init(void);
274 
275 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
276 extern int			fib6_rules_init(void);
277 extern void			fib6_rules_cleanup(void);
278 #else
fib6_rules_init(void)279 static inline int               fib6_rules_init(void)
280 {
281 	return 0;
282 }
fib6_rules_cleanup(void)283 static inline void              fib6_rules_cleanup(void)
284 {
285 	return ;
286 }
287 #endif
288 #endif
289