xref: /linux/include/net/ip6_fib.h (revision d91517839e5d95adc0cf4b28caa7af62a71de526)
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 	u32		fc_type;	/* only 8 bits are used */
41 
42 	struct in6_addr	fc_dst;
43 	struct in6_addr	fc_src;
44 	struct in6_addr	fc_prefsrc;
45 	struct in6_addr	fc_gateway;
46 
47 	unsigned long	fc_expires;
48 	struct nlattr	*fc_mx;
49 	int		fc_mx_len;
50 	int		fc_mp_len;
51 	struct nlattr	*fc_mp;
52 
53 	struct nl_info	fc_nlinfo;
54 };
55 
56 struct fib6_node {
57 	struct fib6_node	*parent;
58 	struct fib6_node	*left;
59 	struct fib6_node	*right;
60 #ifdef CONFIG_IPV6_SUBTREES
61 	struct fib6_node	*subtree;
62 #endif
63 	struct rt6_info		*leaf;
64 
65 	__u16			fn_bit;		/* bit key */
66 	__u16			fn_flags;
67 	__u32			fn_sernum;
68 	struct rt6_info		*rr_ptr;
69 };
70 
71 #ifndef CONFIG_IPV6_SUBTREES
72 #define FIB6_SUBTREE(fn)	NULL
73 #else
74 #define FIB6_SUBTREE(fn)	((fn)->subtree)
75 #endif
76 
77 /*
78  *	routing information
79  *
80  */
81 
82 struct rt6key {
83 	struct in6_addr	addr;
84 	int		plen;
85 };
86 
87 struct fib6_table;
88 
89 struct rt6_info {
90 	struct dst_entry		dst;
91 
92 	/*
93 	 * Tail elements of dst_entry (__refcnt etc.)
94 	 * and these elements (rarely used in hot path) are in
95 	 * the same cache line.
96 	 */
97 	struct fib6_table		*rt6i_table;
98 	struct fib6_node		*rt6i_node;
99 
100 	struct in6_addr			rt6i_gateway;
101 
102 	/* Multipath routes:
103 	 * siblings is a list of rt6_info that have the the same metric/weight,
104 	 * destination, but not the same gateway. nsiblings is just a cache
105 	 * to speed up lookup.
106 	 */
107 	struct list_head		rt6i_siblings;
108 	unsigned int			rt6i_nsiblings;
109 
110 	atomic_t			rt6i_ref;
111 
112 	/* These are in a separate cache line. */
113 	struct rt6key			rt6i_dst ____cacheline_aligned_in_smp;
114 	u32				rt6i_flags;
115 	struct rt6key			rt6i_src;
116 	struct rt6key			rt6i_prefsrc;
117 	u32				rt6i_metric;
118 
119 	struct inet6_dev		*rt6i_idev;
120 	unsigned long			_rt6i_peer;
121 
122 	u32				rt6i_genid;
123 
124 	/* more non-fragment space at head required */
125 	unsigned short			rt6i_nfheader_len;
126 
127 	u8				rt6i_protocol;
128 };
129 
130 static inline struct inet_peer *rt6_peer_ptr(struct rt6_info *rt)
131 {
132 	return inetpeer_ptr(rt->_rt6i_peer);
133 }
134 
135 static inline bool rt6_has_peer(struct rt6_info *rt)
136 {
137 	return inetpeer_ptr_is_peer(rt->_rt6i_peer);
138 }
139 
140 static inline void __rt6_set_peer(struct rt6_info *rt, struct inet_peer *peer)
141 {
142 	__inetpeer_ptr_set_peer(&rt->_rt6i_peer, peer);
143 }
144 
145 static inline bool rt6_set_peer(struct rt6_info *rt, struct inet_peer *peer)
146 {
147 	return inetpeer_ptr_set_peer(&rt->_rt6i_peer, peer);
148 }
149 
150 static inline void rt6_init_peer(struct rt6_info *rt, struct inet_peer_base *base)
151 {
152 	inetpeer_init_ptr(&rt->_rt6i_peer, base);
153 }
154 
155 static inline void rt6_transfer_peer(struct rt6_info *rt, struct rt6_info *ort)
156 {
157 	inetpeer_transfer_peer(&rt->_rt6i_peer, &ort->_rt6i_peer);
158 }
159 
160 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
161 {
162 	return ((struct rt6_info *)dst)->rt6i_idev;
163 }
164 
165 static inline void rt6_clean_expires(struct rt6_info *rt)
166 {
167 	rt->rt6i_flags &= ~RTF_EXPIRES;
168 	rt->dst.expires = 0;
169 }
170 
171 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
172 {
173 	rt->dst.expires = expires;
174 	rt->rt6i_flags |= RTF_EXPIRES;
175 }
176 
177 static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
178 {
179 	struct rt6_info *rt;
180 
181 	for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES);
182 	     rt = (struct rt6_info *)rt->dst.from);
183 	if (rt && rt != rt0)
184 		rt0->dst.expires = rt->dst.expires;
185 
186 	dst_set_expires(&rt0->dst, timeout);
187 	rt0->rt6i_flags |= RTF_EXPIRES;
188 }
189 
190 static inline void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)
191 {
192 	struct dst_entry *new = (struct dst_entry *) from;
193 
194 	rt->rt6i_flags &= ~RTF_EXPIRES;
195 	dst_hold(new);
196 	rt->dst.from = new;
197 }
198 
199 static inline void ip6_rt_put(struct rt6_info *rt)
200 {
201 	/* dst_release() accepts a NULL parameter.
202 	 * We rely on dst being first structure in struct rt6_info
203 	 */
204 	BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
205 	dst_release(&rt->dst);
206 }
207 
208 struct fib6_walker_t {
209 	struct list_head lh;
210 	struct fib6_node *root, *node;
211 	struct rt6_info *leaf;
212 	unsigned char state;
213 	unsigned char prune;
214 	unsigned int skip;
215 	unsigned int count;
216 	int (*func)(struct fib6_walker_t *);
217 	void *args;
218 };
219 
220 struct rt6_statistics {
221 	__u32		fib_nodes;
222 	__u32		fib_route_nodes;
223 	__u32		fib_rt_alloc;		/* permanent routes	*/
224 	__u32		fib_rt_entries;		/* rt entries in table	*/
225 	__u32		fib_rt_cache;		/* cache routes		*/
226 	__u32		fib_discarded_routes;
227 };
228 
229 #define RTN_TL_ROOT	0x0001
230 #define RTN_ROOT	0x0002		/* tree root node		*/
231 #define RTN_RTINFO	0x0004		/* node with valid routing info	*/
232 
233 /*
234  *	priority levels (or metrics)
235  *
236  */
237 
238 
239 struct fib6_table {
240 	struct hlist_node	tb6_hlist;
241 	u32			tb6_id;
242 	rwlock_t		tb6_lock;
243 	struct fib6_node	tb6_root;
244 	struct inet_peer_base	tb6_peers;
245 };
246 
247 #define RT6_TABLE_UNSPEC	RT_TABLE_UNSPEC
248 #define RT6_TABLE_MAIN		RT_TABLE_MAIN
249 #define RT6_TABLE_DFLT		RT6_TABLE_MAIN
250 #define RT6_TABLE_INFO		RT6_TABLE_MAIN
251 #define RT6_TABLE_PREFIX	RT6_TABLE_MAIN
252 
253 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
254 #define FIB6_TABLE_MIN		1
255 #define FIB6_TABLE_MAX		RT_TABLE_MAX
256 #define RT6_TABLE_LOCAL		RT_TABLE_LOCAL
257 #else
258 #define FIB6_TABLE_MIN		RT_TABLE_MAIN
259 #define FIB6_TABLE_MAX		FIB6_TABLE_MIN
260 #define RT6_TABLE_LOCAL		RT6_TABLE_MAIN
261 #endif
262 
263 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
264 					 struct fib6_table *,
265 					 struct flowi6 *, int);
266 
267 /*
268  *	exported functions
269  */
270 
271 struct fib6_table *fib6_get_table(struct net *net, u32 id);
272 struct fib6_table *fib6_new_table(struct net *net, u32 id);
273 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
274 				   int flags, pol_lookup_t lookup);
275 
276 struct fib6_node *fib6_lookup(struct fib6_node *root,
277 			      const struct in6_addr *daddr,
278 			      const struct in6_addr *saddr);
279 
280 struct fib6_node *fib6_locate(struct fib6_node *root,
281 			      const struct in6_addr *daddr, int dst_len,
282 			      const struct in6_addr *saddr, int src_len);
283 
284 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
285 		    void *arg);
286 
287 int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info);
288 
289 int fib6_del(struct rt6_info *rt, struct nl_info *info);
290 
291 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info);
292 
293 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
294 
295 void fib6_gc_cleanup(void);
296 
297 int fib6_init(void);
298 
299 int ipv6_route_open(struct inode *inode, struct file *file);
300 
301 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
302 int fib6_rules_init(void);
303 void fib6_rules_cleanup(void);
304 #else
305 static inline int               fib6_rules_init(void)
306 {
307 	return 0;
308 }
309 static inline void              fib6_rules_cleanup(void)
310 {
311 	return ;
312 }
313 #endif
314 #endif
315