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 #define RT6_DEBUG 2
33
34 #if RT6_DEBUG >= 3
35 #define RT6_TRACE(x...) pr_debug(x)
36 #else
37 #define RT6_TRACE(x...) do { ; } while (0)
38 #endif
39
40 struct rt6_info;
41 struct fib6_info;
42
43 struct fib6_config {
44 u32 fc_table;
45 u32 fc_metric;
46 int fc_dst_len;
47 int fc_src_len;
48 int fc_ifindex;
49 u32 fc_flags;
50 u32 fc_protocol;
51 u16 fc_type; /* only 8 bits are used */
52 u16 fc_delete_all_nh : 1,
53 __unused : 15;
54
55 struct in6_addr fc_dst;
56 struct in6_addr fc_src;
57 struct in6_addr fc_prefsrc;
58 struct in6_addr fc_gateway;
59
60 unsigned long fc_expires;
61 struct nlattr *fc_mx;
62 int fc_mx_len;
63 int fc_mp_len;
64 struct nlattr *fc_mp;
65
66 struct nl_info fc_nlinfo;
67 struct nlattr *fc_encap;
68 u16 fc_encap_type;
69 };
70
71 struct fib6_node {
72 struct fib6_node __rcu *parent;
73 struct fib6_node __rcu *left;
74 struct fib6_node __rcu *right;
75 #ifdef CONFIG_IPV6_SUBTREES
76 struct fib6_node __rcu *subtree;
77 #endif
78 struct fib6_info __rcu *leaf;
79
80 __u16 fn_bit; /* bit key */
81 __u16 fn_flags;
82 int fn_sernum;
83 struct fib6_info __rcu *rr_ptr;
84 struct rcu_head rcu;
85 };
86
87 struct fib6_gc_args {
88 int timeout;
89 int more;
90 };
91
92 #ifndef CONFIG_IPV6_SUBTREES
93 #define FIB6_SUBTREE(fn) NULL
94 #else
95 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
96 #endif
97
98 /*
99 * routing information
100 *
101 */
102
103 struct rt6key {
104 struct in6_addr addr;
105 int plen;
106 };
107
108 struct fib6_table;
109
110 struct rt6_exception_bucket {
111 struct hlist_head chain;
112 int depth;
113 };
114
115 struct rt6_exception {
116 struct hlist_node hlist;
117 struct rt6_info *rt6i;
118 unsigned long stamp;
119 struct rcu_head rcu;
120 };
121
122 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
123 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
124 #define FIB6_MAX_DEPTH 5
125
126 struct fib6_nh {
127 struct in6_addr nh_gw;
128 struct net_device *nh_dev;
129 struct lwtunnel_state *nh_lwtstate;
130
131 unsigned int nh_flags;
132 atomic_t nh_upper_bound;
133 int nh_weight;
134 };
135
136 struct fib6_info {
137 struct fib6_table *fib6_table;
138 struct fib6_info __rcu *fib6_next;
139 struct fib6_node __rcu *fib6_node;
140
141 /* Multipath routes:
142 * siblings is a list of fib6_info that have the the same metric/weight,
143 * destination, but not the same gateway. nsiblings is just a cache
144 * to speed up lookup.
145 */
146 struct list_head fib6_siblings;
147 unsigned int fib6_nsiblings;
148
149 atomic_t fib6_ref;
150 unsigned long expires;
151 struct dst_metrics *fib6_metrics;
152 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
153
154 struct rt6key fib6_dst;
155 u32 fib6_flags;
156 struct rt6key fib6_src;
157 struct rt6key fib6_prefsrc;
158
159 struct rt6_info * __percpu *rt6i_pcpu;
160 struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
161
162 #ifdef CONFIG_IPV6_ROUTER_PREF
163 unsigned long last_probe;
164 #endif
165
166 u32 fib6_metric;
167 u8 fib6_protocol;
168 u8 fib6_type;
169 u8 exception_bucket_flushed:1,
170 should_flush:1,
171 dst_nocount:1,
172 dst_nopolicy:1,
173 dst_host:1,
174 fib6_destroying:1,
175 unused:2;
176
177 struct fib6_nh fib6_nh;
178 struct rcu_head rcu;
179 };
180
181 struct rt6_info {
182 struct dst_entry dst;
183 struct fib6_info __rcu *from;
184
185 struct rt6key rt6i_dst;
186 struct rt6key rt6i_src;
187 struct in6_addr rt6i_gateway;
188 struct inet6_dev *rt6i_idev;
189 u32 rt6i_flags;
190 struct rt6key rt6i_prefsrc;
191
192 struct list_head rt6i_uncached;
193 struct uncached_list *rt6i_uncached_list;
194
195 /* more non-fragment space at head required */
196 unsigned short rt6i_nfheader_len;
197 };
198
199 #define for_each_fib6_node_rt_rcu(fn) \
200 for (rt = rcu_dereference((fn)->leaf); rt; \
201 rt = rcu_dereference(rt->fib6_next))
202
203 #define for_each_fib6_walker_rt(w) \
204 for (rt = (w)->leaf; rt; \
205 rt = rcu_dereference_protected(rt->fib6_next, 1))
206
ip6_dst_idev(struct dst_entry * dst)207 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
208 {
209 return ((struct rt6_info *)dst)->rt6i_idev;
210 }
211
fib6_clean_expires(struct fib6_info * f6i)212 static inline void fib6_clean_expires(struct fib6_info *f6i)
213 {
214 f6i->fib6_flags &= ~RTF_EXPIRES;
215 f6i->expires = 0;
216 }
217
fib6_set_expires(struct fib6_info * f6i,unsigned long expires)218 static inline void fib6_set_expires(struct fib6_info *f6i,
219 unsigned long expires)
220 {
221 f6i->expires = expires;
222 f6i->fib6_flags |= RTF_EXPIRES;
223 }
224
fib6_check_expired(const struct fib6_info * f6i)225 static inline bool fib6_check_expired(const struct fib6_info *f6i)
226 {
227 if (f6i->fib6_flags & RTF_EXPIRES)
228 return time_after(jiffies, f6i->expires);
229 return false;
230 }
231
232 /* Function to safely get fn->sernum for passed in rt
233 * and store result in passed in cookie.
234 * Return true if we can get cookie safely
235 * Return false if not
236 */
fib6_get_cookie_safe(const struct fib6_info * f6i,u32 * cookie)237 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
238 u32 *cookie)
239 {
240 struct fib6_node *fn;
241 bool status = false;
242
243 fn = rcu_dereference(f6i->fib6_node);
244
245 if (fn) {
246 *cookie = READ_ONCE(fn->fn_sernum);
247 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
248 smp_rmb();
249 status = true;
250 }
251
252 return status;
253 }
254
rt6_get_cookie(const struct rt6_info * rt)255 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
256 {
257 struct fib6_info *from;
258 u32 cookie = 0;
259
260 rcu_read_lock();
261
262 from = rcu_dereference(rt->from);
263 if (from)
264 fib6_get_cookie_safe(from, &cookie);
265
266 rcu_read_unlock();
267
268 return cookie;
269 }
270
ip6_rt_put(struct rt6_info * rt)271 static inline void ip6_rt_put(struct rt6_info *rt)
272 {
273 /* dst_release() accepts a NULL parameter.
274 * We rely on dst being first structure in struct rt6_info
275 */
276 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
277 dst_release(&rt->dst);
278 }
279
280 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags);
281 void fib6_info_destroy_rcu(struct rcu_head *head);
282
fib6_info_hold(struct fib6_info * f6i)283 static inline void fib6_info_hold(struct fib6_info *f6i)
284 {
285 atomic_inc(&f6i->fib6_ref);
286 }
287
fib6_info_hold_safe(struct fib6_info * f6i)288 static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
289 {
290 return atomic_inc_not_zero(&f6i->fib6_ref);
291 }
292
fib6_info_release(struct fib6_info * f6i)293 static inline void fib6_info_release(struct fib6_info *f6i)
294 {
295 if (f6i && atomic_dec_and_test(&f6i->fib6_ref))
296 call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
297 }
298
299 enum fib6_walk_state {
300 #ifdef CONFIG_IPV6_SUBTREES
301 FWS_S,
302 #endif
303 FWS_L,
304 FWS_R,
305 FWS_C,
306 FWS_U
307 };
308
309 struct fib6_walker {
310 struct list_head lh;
311 struct fib6_node *root, *node;
312 struct fib6_info *leaf;
313 enum fib6_walk_state state;
314 unsigned int skip;
315 unsigned int count;
316 int (*func)(struct fib6_walker *);
317 void *args;
318 };
319
320 struct rt6_statistics {
321 __u32 fib_nodes; /* all fib6 nodes */
322 __u32 fib_route_nodes; /* intermediate nodes */
323 __u32 fib_rt_entries; /* rt entries in fib table */
324 __u32 fib_rt_cache; /* cached rt entries in exception table */
325 __u32 fib_discarded_routes; /* total number of routes delete */
326
327 /* The following stats are not protected by any lock */
328 atomic_t fib_rt_alloc; /* total number of routes alloced */
329 atomic_t fib_rt_uncache; /* rt entries in uncached list */
330 };
331
332 #define RTN_TL_ROOT 0x0001
333 #define RTN_ROOT 0x0002 /* tree root node */
334 #define RTN_RTINFO 0x0004 /* node with valid routing info */
335
336 /*
337 * priority levels (or metrics)
338 *
339 */
340
341
342 struct fib6_table {
343 struct hlist_node tb6_hlist;
344 u32 tb6_id;
345 spinlock_t tb6_lock;
346 struct fib6_node tb6_root;
347 struct inet_peer_base tb6_peers;
348 unsigned int flags;
349 unsigned int fib_seq;
350 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
351 };
352
353 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
354 #define RT6_TABLE_MAIN RT_TABLE_MAIN
355 #define RT6_TABLE_DFLT RT6_TABLE_MAIN
356 #define RT6_TABLE_INFO RT6_TABLE_MAIN
357 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN
358
359 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
360 #define FIB6_TABLE_MIN 1
361 #define FIB6_TABLE_MAX RT_TABLE_MAX
362 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL
363 #else
364 #define FIB6_TABLE_MIN RT_TABLE_MAIN
365 #define FIB6_TABLE_MAX FIB6_TABLE_MIN
366 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN
367 #endif
368
369 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
370 struct fib6_table *,
371 struct flowi6 *,
372 const struct sk_buff *, int);
373
374 struct fib6_entry_notifier_info {
375 struct fib_notifier_info info; /* must be first */
376 struct fib6_info *rt;
377 };
378
379 /*
380 * exported functions
381 */
382
383 struct fib6_table *fib6_get_table(struct net *net, u32 id);
384 struct fib6_table *fib6_new_table(struct net *net, u32 id);
385 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
386 const struct sk_buff *skb,
387 int flags, pol_lookup_t lookup);
388
389 /* called with rcu lock held; can return error pointer
390 * caller needs to select path
391 */
392 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
393 int flags);
394
395 /* called with rcu lock held; caller needs to select path */
396 struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table,
397 int oif, struct flowi6 *fl6, int strict);
398
399 struct fib6_info *fib6_multipath_select(const struct net *net,
400 struct fib6_info *match,
401 struct flowi6 *fl6, int oif,
402 const struct sk_buff *skb, int strict);
403
404 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
405 const struct in6_addr *daddr,
406 const struct in6_addr *saddr);
407
408 struct fib6_node *fib6_locate(struct fib6_node *root,
409 const struct in6_addr *daddr, int dst_len,
410 const struct in6_addr *saddr, int src_len,
411 bool exact_match);
412
413 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
414 void *arg);
415
416 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
417 struct nl_info *info, struct netlink_ext_ack *extack);
418 int fib6_del(struct fib6_info *rt, struct nl_info *info);
419
fib6_info_nh_dev(const struct fib6_info * f6i)420 static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i)
421 {
422 return f6i->fib6_nh.nh_dev;
423 }
424
425 static inline
fib6_info_nh_lwt(const struct fib6_info * f6i)426 struct lwtunnel_state *fib6_info_nh_lwt(const struct fib6_info *f6i)
427 {
428 return f6i->fib6_nh.nh_lwtstate;
429 }
430
431 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
432 unsigned int flags);
433
434 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
435
436 void fib6_gc_cleanup(void);
437
438 int fib6_init(void);
439
440 struct ipv6_route_iter {
441 struct seq_net_private p;
442 struct fib6_walker w;
443 loff_t skip;
444 struct fib6_table *tbl;
445 int sernum;
446 };
447
448 extern const struct seq_operations ipv6_route_seq_ops;
449
450 int call_fib6_notifier(struct notifier_block *nb, struct net *net,
451 enum fib_event_type event_type,
452 struct fib_notifier_info *info);
453 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
454 struct fib_notifier_info *info);
455
456 int __net_init fib6_notifier_init(struct net *net);
457 void __net_exit fib6_notifier_exit(struct net *net);
458
459 unsigned int fib6_tables_seq_read(struct net *net);
460 int fib6_tables_dump(struct net *net, struct notifier_block *nb);
461
462 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
463 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
464
465 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
fib6_metric_locked(struct fib6_info * f6i,int metric)466 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
467 {
468 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
469 }
470
471 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
472 int fib6_rules_init(void);
473 void fib6_rules_cleanup(void);
474 bool fib6_rule_default(const struct fib_rule *rule);
475 int fib6_rules_dump(struct net *net, struct notifier_block *nb);
476 unsigned int fib6_rules_seq_read(struct net *net);
477
fib6_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi6 * fl6,struct flow_keys * flkeys)478 static inline bool fib6_rules_early_flow_dissect(struct net *net,
479 struct sk_buff *skb,
480 struct flowi6 *fl6,
481 struct flow_keys *flkeys)
482 {
483 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
484
485 if (!net->ipv6.fib6_rules_require_fldissect)
486 return false;
487
488 skb_flow_dissect_flow_keys(skb, flkeys, flag);
489 fl6->fl6_sport = flkeys->ports.src;
490 fl6->fl6_dport = flkeys->ports.dst;
491 fl6->flowi6_proto = flkeys->basic.ip_proto;
492
493 return true;
494 }
495 #else
fib6_rules_init(void)496 static inline int fib6_rules_init(void)
497 {
498 return 0;
499 }
fib6_rules_cleanup(void)500 static inline void fib6_rules_cleanup(void)
501 {
502 return ;
503 }
fib6_rule_default(const struct fib_rule * rule)504 static inline bool fib6_rule_default(const struct fib_rule *rule)
505 {
506 return true;
507 }
fib6_rules_dump(struct net * net,struct notifier_block * nb)508 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb)
509 {
510 return 0;
511 }
fib6_rules_seq_read(struct net * net)512 static inline unsigned int fib6_rules_seq_read(struct net *net)
513 {
514 return 0;
515 }
fib6_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi6 * fl6,struct flow_keys * flkeys)516 static inline bool fib6_rules_early_flow_dissect(struct net *net,
517 struct sk_buff *skb,
518 struct flowi6 *fl6,
519 struct flow_keys *flkeys)
520 {
521 return false;
522 }
523 #endif
524 #endif
525