xref: /linux/include/net/ip6_fib.h (revision 2ba9268dd603d23e17643437b2246acb6844953b)
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 	int			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 struct mx6_config {
78 	const u32 *mx;
79 	DECLARE_BITMAP(mx_valid, RTAX_MAX);
80 };
81 
82 /*
83  *	routing information
84  *
85  */
86 
87 struct rt6key {
88 	struct in6_addr	addr;
89 	int		plen;
90 };
91 
92 struct fib6_table;
93 
94 struct rt6_info {
95 	struct dst_entry		dst;
96 
97 	/*
98 	 * Tail elements of dst_entry (__refcnt etc.)
99 	 * and these elements (rarely used in hot path) are in
100 	 * the same cache line.
101 	 */
102 	struct fib6_table		*rt6i_table;
103 	struct fib6_node		*rt6i_node;
104 
105 	struct in6_addr			rt6i_gateway;
106 
107 	/* Multipath routes:
108 	 * siblings is a list of rt6_info that have the the same metric/weight,
109 	 * destination, but not the same gateway. nsiblings is just a cache
110 	 * to speed up lookup.
111 	 */
112 	struct list_head		rt6i_siblings;
113 	unsigned int			rt6i_nsiblings;
114 
115 	atomic_t			rt6i_ref;
116 
117 	/* These are in a separate cache line. */
118 	struct rt6key			rt6i_dst ____cacheline_aligned_in_smp;
119 	u32				rt6i_flags;
120 	struct rt6key			rt6i_src;
121 	struct rt6key			rt6i_prefsrc;
122 
123 	struct inet6_dev		*rt6i_idev;
124 	unsigned long			_rt6i_peer;
125 
126 	u32				rt6i_metric;
127 	/* more non-fragment space at head required */
128 	unsigned short			rt6i_nfheader_len;
129 	u8				rt6i_protocol;
130 };
131 
132 static inline struct inet_peer *rt6_peer_ptr(struct rt6_info *rt)
133 {
134 	return inetpeer_ptr(rt->_rt6i_peer);
135 }
136 
137 static inline bool rt6_has_peer(struct rt6_info *rt)
138 {
139 	return inetpeer_ptr_is_peer(rt->_rt6i_peer);
140 }
141 
142 static inline void __rt6_set_peer(struct rt6_info *rt, struct inet_peer *peer)
143 {
144 	__inetpeer_ptr_set_peer(&rt->_rt6i_peer, peer);
145 }
146 
147 static inline bool rt6_set_peer(struct rt6_info *rt, struct inet_peer *peer)
148 {
149 	return inetpeer_ptr_set_peer(&rt->_rt6i_peer, peer);
150 }
151 
152 static inline void rt6_init_peer(struct rt6_info *rt, struct inet_peer_base *base)
153 {
154 	inetpeer_init_ptr(&rt->_rt6i_peer, base);
155 }
156 
157 static inline void rt6_transfer_peer(struct rt6_info *rt, struct rt6_info *ort)
158 {
159 	inetpeer_transfer_peer(&rt->_rt6i_peer, &ort->_rt6i_peer);
160 }
161 
162 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
163 {
164 	return ((struct rt6_info *)dst)->rt6i_idev;
165 }
166 
167 static inline void rt6_clean_expires(struct rt6_info *rt)
168 {
169 	rt->rt6i_flags &= ~RTF_EXPIRES;
170 	rt->dst.expires = 0;
171 }
172 
173 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
174 {
175 	rt->dst.expires = expires;
176 	rt->rt6i_flags |= RTF_EXPIRES;
177 }
178 
179 static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
180 {
181 	struct rt6_info *rt;
182 
183 	for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES);
184 	     rt = (struct rt6_info *)rt->dst.from);
185 	if (rt && rt != rt0)
186 		rt0->dst.expires = rt->dst.expires;
187 
188 	dst_set_expires(&rt0->dst, timeout);
189 	rt0->rt6i_flags |= RTF_EXPIRES;
190 }
191 
192 static inline void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)
193 {
194 	struct dst_entry *new = (struct dst_entry *) from;
195 
196 	rt->rt6i_flags &= ~RTF_EXPIRES;
197 	dst_hold(new);
198 	rt->dst.from = new;
199 }
200 
201 static inline void ip6_rt_put(struct rt6_info *rt)
202 {
203 	/* dst_release() accepts a NULL parameter.
204 	 * We rely on dst being first structure in struct rt6_info
205 	 */
206 	BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
207 	dst_release(&rt->dst);
208 }
209 
210 enum fib6_walk_state {
211 #ifdef CONFIG_IPV6_SUBTREES
212 	FWS_S,
213 #endif
214 	FWS_L,
215 	FWS_R,
216 	FWS_C,
217 	FWS_U
218 };
219 
220 struct fib6_walker {
221 	struct list_head lh;
222 	struct fib6_node *root, *node;
223 	struct rt6_info *leaf;
224 	enum fib6_walk_state state;
225 	bool prune;
226 	unsigned int skip;
227 	unsigned int count;
228 	int (*func)(struct fib6_walker *);
229 	void *args;
230 };
231 
232 struct rt6_statistics {
233 	__u32		fib_nodes;
234 	__u32		fib_route_nodes;
235 	__u32		fib_rt_alloc;		/* permanent routes	*/
236 	__u32		fib_rt_entries;		/* rt entries in table	*/
237 	__u32		fib_rt_cache;		/* cache routes		*/
238 	__u32		fib_discarded_routes;
239 };
240 
241 #define RTN_TL_ROOT	0x0001
242 #define RTN_ROOT	0x0002		/* tree root node		*/
243 #define RTN_RTINFO	0x0004		/* node with valid routing info	*/
244 
245 /*
246  *	priority levels (or metrics)
247  *
248  */
249 
250 
251 struct fib6_table {
252 	struct hlist_node	tb6_hlist;
253 	u32			tb6_id;
254 	rwlock_t		tb6_lock;
255 	struct fib6_node	tb6_root;
256 	struct inet_peer_base	tb6_peers;
257 };
258 
259 #define RT6_TABLE_UNSPEC	RT_TABLE_UNSPEC
260 #define RT6_TABLE_MAIN		RT_TABLE_MAIN
261 #define RT6_TABLE_DFLT		RT6_TABLE_MAIN
262 #define RT6_TABLE_INFO		RT6_TABLE_MAIN
263 #define RT6_TABLE_PREFIX	RT6_TABLE_MAIN
264 
265 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
266 #define FIB6_TABLE_MIN		1
267 #define FIB6_TABLE_MAX		RT_TABLE_MAX
268 #define RT6_TABLE_LOCAL		RT_TABLE_LOCAL
269 #else
270 #define FIB6_TABLE_MIN		RT_TABLE_MAIN
271 #define FIB6_TABLE_MAX		FIB6_TABLE_MIN
272 #define RT6_TABLE_LOCAL		RT6_TABLE_MAIN
273 #endif
274 
275 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
276 					 struct fib6_table *,
277 					 struct flowi6 *, int);
278 
279 /*
280  *	exported functions
281  */
282 
283 struct fib6_table *fib6_get_table(struct net *net, u32 id);
284 struct fib6_table *fib6_new_table(struct net *net, u32 id);
285 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
286 				   int flags, pol_lookup_t lookup);
287 
288 struct fib6_node *fib6_lookup(struct fib6_node *root,
289 			      const struct in6_addr *daddr,
290 			      const struct in6_addr *saddr);
291 
292 struct fib6_node *fib6_locate(struct fib6_node *root,
293 			      const struct in6_addr *daddr, int dst_len,
294 			      const struct in6_addr *saddr, int src_len);
295 
296 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
297 		    void *arg);
298 
299 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
300 	     struct nl_info *info, struct mx6_config *mxc);
301 int fib6_del(struct rt6_info *rt, struct nl_info *info);
302 
303 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info);
304 
305 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
306 
307 void fib6_gc_cleanup(void);
308 
309 int fib6_init(void);
310 
311 int ipv6_route_open(struct inode *inode, struct file *file);
312 
313 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
314 int fib6_rules_init(void);
315 void fib6_rules_cleanup(void);
316 #else
317 static inline int               fib6_rules_init(void)
318 {
319 	return 0;
320 }
321 static inline void              fib6_rules_cleanup(void)
322 {
323 	return ;
324 }
325 #endif
326 #endif
327