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 <linux/notifier.h>
20 #include <net/dst.h>
21 #include <net/flow.h>
22 #include <net/netlink.h>
23 #include <net/inetpeer.h>
24 #include <net/fib_notifier.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 u16 fc_type; /* only 8 bits are used */
43 u16 fc_delete_all_nh : 1,
44 __unused : 15;
45
46 struct in6_addr fc_dst;
47 struct in6_addr fc_src;
48 struct in6_addr fc_prefsrc;
49 struct in6_addr fc_gateway;
50
51 unsigned long fc_expires;
52 struct nlattr *fc_mx;
53 int fc_mx_len;
54 int fc_mp_len;
55 struct nlattr *fc_mp;
56
57 struct nl_info fc_nlinfo;
58 struct nlattr *fc_encap;
59 u16 fc_encap_type;
60 };
61
62 struct fib6_node {
63 struct fib6_node *parent;
64 struct fib6_node *left;
65 struct fib6_node *right;
66 #ifdef CONFIG_IPV6_SUBTREES
67 struct fib6_node *subtree;
68 #endif
69 struct rt6_info *leaf;
70
71 __u16 fn_bit; /* bit key */
72 __u16 fn_flags;
73 int fn_sernum;
74 struct rt6_info *rr_ptr;
75 struct rcu_head rcu;
76 };
77
78 #ifndef CONFIG_IPV6_SUBTREES
79 #define FIB6_SUBTREE(fn) NULL
80 #else
81 #define FIB6_SUBTREE(fn) ((fn)->subtree)
82 #endif
83
84 struct mx6_config {
85 const u32 *mx;
86 DECLARE_BITMAP(mx_valid, RTAX_MAX);
87 };
88
89 /*
90 * routing information
91 *
92 */
93
94 struct rt6key {
95 struct in6_addr addr;
96 int plen;
97 };
98
99 struct fib6_table;
100
101 struct rt6_info {
102 struct dst_entry dst;
103
104 /*
105 * Tail elements of dst_entry (__refcnt etc.)
106 * and these elements (rarely used in hot path) are in
107 * the same cache line.
108 */
109 struct fib6_table *rt6i_table;
110 struct fib6_node __rcu *rt6i_node;
111
112 struct in6_addr rt6i_gateway;
113
114 /* Multipath routes:
115 * siblings is a list of rt6_info that have the the same metric/weight,
116 * destination, but not the same gateway. nsiblings is just a cache
117 * to speed up lookup.
118 */
119 struct list_head rt6i_siblings;
120 unsigned int rt6i_nsiblings;
121
122 atomic_t rt6i_ref;
123
124 unsigned int rt6i_nh_flags;
125
126 /* These are in a separate cache line. */
127 struct rt6key rt6i_dst ____cacheline_aligned_in_smp;
128 u32 rt6i_flags;
129 struct rt6key rt6i_src;
130 struct rt6key rt6i_prefsrc;
131
132 struct list_head rt6i_uncached;
133 struct uncached_list *rt6i_uncached_list;
134
135 struct inet6_dev *rt6i_idev;
136 struct rt6_info * __percpu *rt6i_pcpu;
137
138 u32 rt6i_metric;
139 u32 rt6i_pmtu;
140 /* more non-fragment space at head required */
141 unsigned short rt6i_nfheader_len;
142 u8 rt6i_protocol;
143 };
144
ip6_dst_idev(struct dst_entry * dst)145 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
146 {
147 return ((struct rt6_info *)dst)->rt6i_idev;
148 }
149
rt6_clean_expires(struct rt6_info * rt)150 static inline void rt6_clean_expires(struct rt6_info *rt)
151 {
152 rt->rt6i_flags &= ~RTF_EXPIRES;
153 rt->dst.expires = 0;
154 }
155
rt6_set_expires(struct rt6_info * rt,unsigned long expires)156 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
157 {
158 rt->dst.expires = expires;
159 rt->rt6i_flags |= RTF_EXPIRES;
160 }
161
rt6_update_expires(struct rt6_info * rt0,int timeout)162 static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
163 {
164 struct rt6_info *rt;
165
166 for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES);
167 rt = (struct rt6_info *)rt->dst.from);
168 if (rt && rt != rt0)
169 rt0->dst.expires = rt->dst.expires;
170
171 dst_set_expires(&rt0->dst, timeout);
172 rt0->rt6i_flags |= RTF_EXPIRES;
173 }
174
175 /* Function to safely get fn->sernum for passed in rt
176 * and store result in passed in cookie.
177 * Return true if we can get cookie safely
178 * Return false if not
179 */
rt6_get_cookie_safe(const struct rt6_info * rt,u32 * cookie)180 static inline bool rt6_get_cookie_safe(const struct rt6_info *rt,
181 u32 *cookie)
182 {
183 struct fib6_node *fn;
184 bool status = false;
185
186 rcu_read_lock();
187 fn = rcu_dereference(rt->rt6i_node);
188
189 if (fn) {
190 *cookie = fn->fn_sernum;
191 status = true;
192 }
193
194 rcu_read_unlock();
195 return status;
196 }
197
rt6_get_cookie(const struct rt6_info * rt)198 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
199 {
200 u32 cookie = 0;
201
202 if (rt->dst.from)
203 rt = (struct rt6_info *)(rt->dst.from);
204
205 rt6_get_cookie_safe(rt, &cookie);
206
207 return cookie;
208 }
209
ip6_rt_put(struct rt6_info * rt)210 static inline void ip6_rt_put(struct rt6_info *rt)
211 {
212 /* dst_release() accepts a NULL parameter.
213 * We rely on dst being first structure in struct rt6_info
214 */
215 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
216 dst_release(&rt->dst);
217 }
218
219 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt);
220
rt6_hold(struct rt6_info * rt)221 static inline void rt6_hold(struct rt6_info *rt)
222 {
223 atomic_inc(&rt->rt6i_ref);
224 }
225
rt6_release(struct rt6_info * rt)226 static inline void rt6_release(struct rt6_info *rt)
227 {
228 if (atomic_dec_and_test(&rt->rt6i_ref)) {
229 rt6_free_pcpu(rt);
230 dst_dev_put(&rt->dst);
231 dst_release(&rt->dst);
232 }
233 }
234
235 enum fib6_walk_state {
236 #ifdef CONFIG_IPV6_SUBTREES
237 FWS_S,
238 #endif
239 FWS_L,
240 FWS_R,
241 FWS_C,
242 FWS_U
243 };
244
245 struct fib6_walker {
246 struct list_head lh;
247 struct fib6_node *root, *node;
248 struct rt6_info *leaf;
249 enum fib6_walk_state state;
250 bool prune;
251 unsigned int skip;
252 unsigned int count;
253 int (*func)(struct fib6_walker *);
254 void *args;
255 };
256
257 struct rt6_statistics {
258 __u32 fib_nodes;
259 __u32 fib_route_nodes;
260 __u32 fib_rt_alloc; /* permanent routes */
261 __u32 fib_rt_entries; /* rt entries in table */
262 __u32 fib_rt_cache; /* cache routes */
263 __u32 fib_discarded_routes;
264 };
265
266 #define RTN_TL_ROOT 0x0001
267 #define RTN_ROOT 0x0002 /* tree root node */
268 #define RTN_RTINFO 0x0004 /* node with valid routing info */
269
270 /*
271 * priority levels (or metrics)
272 *
273 */
274
275
276 struct fib6_table {
277 struct hlist_node tb6_hlist;
278 u32 tb6_id;
279 rwlock_t tb6_lock;
280 struct fib6_node tb6_root;
281 struct inet_peer_base tb6_peers;
282 unsigned int flags;
283 unsigned int fib_seq;
284 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
285 };
286
287 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
288 #define RT6_TABLE_MAIN RT_TABLE_MAIN
289 #define RT6_TABLE_DFLT RT6_TABLE_MAIN
290 #define RT6_TABLE_INFO RT6_TABLE_MAIN
291 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN
292
293 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
294 #define FIB6_TABLE_MIN 1
295 #define FIB6_TABLE_MAX RT_TABLE_MAX
296 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL
297 #else
298 #define FIB6_TABLE_MIN RT_TABLE_MAIN
299 #define FIB6_TABLE_MAX FIB6_TABLE_MIN
300 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN
301 #endif
302
303 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
304 struct fib6_table *,
305 struct flowi6 *, int);
306
307 struct fib6_entry_notifier_info {
308 struct fib_notifier_info info; /* must be first */
309 struct rt6_info *rt;
310 };
311
312 /*
313 * exported functions
314 */
315
316 struct fib6_table *fib6_get_table(struct net *net, u32 id);
317 struct fib6_table *fib6_new_table(struct net *net, u32 id);
318 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
319 int flags, pol_lookup_t lookup);
320
321 struct fib6_node *fib6_lookup(struct fib6_node *root,
322 const struct in6_addr *daddr,
323 const struct in6_addr *saddr);
324
325 struct fib6_node *fib6_locate(struct fib6_node *root,
326 const struct in6_addr *daddr, int dst_len,
327 const struct in6_addr *saddr, int src_len);
328
329 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
330 void *arg);
331
332 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
333 struct nl_info *info, struct mx6_config *mxc,
334 struct netlink_ext_ack *extack);
335 int fib6_del(struct rt6_info *rt, struct nl_info *info);
336
337 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info,
338 unsigned int flags);
339
340 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
341
342 void fib6_gc_cleanup(void);
343
344 int fib6_init(void);
345
346 int ipv6_route_open(struct inode *inode, struct file *file);
347
348 int call_fib6_notifier(struct notifier_block *nb, struct net *net,
349 enum fib_event_type event_type,
350 struct fib_notifier_info *info);
351 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
352 struct fib_notifier_info *info);
353
354 int __net_init fib6_notifier_init(struct net *net);
355 void __net_exit fib6_notifier_exit(struct net *net);
356
357 unsigned int fib6_tables_seq_read(struct net *net);
358 int fib6_tables_dump(struct net *net, struct notifier_block *nb);
359
360 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
361 int fib6_rules_init(void);
362 void fib6_rules_cleanup(void);
363 bool fib6_rule_default(const struct fib_rule *rule);
364 int fib6_rules_dump(struct net *net, struct notifier_block *nb);
365 unsigned int fib6_rules_seq_read(struct net *net);
366 #else
fib6_rules_init(void)367 static inline int fib6_rules_init(void)
368 {
369 return 0;
370 }
fib6_rules_cleanup(void)371 static inline void fib6_rules_cleanup(void)
372 {
373 return ;
374 }
fib6_rule_default(const struct fib_rule * rule)375 static inline bool fib6_rule_default(const struct fib_rule *rule)
376 {
377 return true;
378 }
fib6_rules_dump(struct net * net,struct notifier_block * nb)379 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb)
380 {
381 return 0;
382 }
fib6_rules_seq_read(struct net * net)383 static inline unsigned int fib6_rules_seq_read(struct net *net)
384 {
385 return 0;
386 }
387 #endif
388 #endif
389