1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 */
8
9 #ifndef _IP6_FIB_H
10 #define _IP6_FIB_H
11
12 #include <linux/ipv6_route.h>
13 #include <linux/rtnetlink.h>
14 #include <linux/spinlock.h>
15 #include <linux/notifier.h>
16 #include <net/dst.h>
17 #include <net/flow.h>
18 #include <net/ip_fib.h>
19 #include <net/netlink.h>
20 #include <net/inetpeer.h>
21 #include <net/fib_notifier.h>
22
23 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
24 #define FIB6_TABLE_HASHSZ 256
25 #else
26 #define FIB6_TABLE_HASHSZ 1
27 #endif
28
29 #define RT6_DEBUG 2
30
31 #if RT6_DEBUG >= 3
32 #define RT6_TRACE(x...) pr_debug(x)
33 #else
34 #define RT6_TRACE(x...) do { ; } while (0)
35 #endif
36
37 struct rt6_info;
38 struct fib6_info;
39
40 struct fib6_config {
41 u32 fc_table;
42 u32 fc_metric;
43 int fc_dst_len;
44 int fc_src_len;
45 int fc_ifindex;
46 u32 fc_flags;
47 u32 fc_protocol;
48 u16 fc_type; /* only 8 bits are used */
49 u16 fc_delete_all_nh : 1,
50 fc_ignore_dev_down:1,
51 __unused : 14;
52 u32 fc_nh_id;
53
54 struct in6_addr fc_dst;
55 struct in6_addr fc_src;
56 struct in6_addr fc_prefsrc;
57 struct in6_addr fc_gateway;
58
59 unsigned long fc_expires;
60 struct nlattr *fc_mx;
61 int fc_mx_len;
62 int fc_mp_len;
63 struct nlattr *fc_mp;
64
65 struct nl_info fc_nlinfo;
66 struct nlattr *fc_encap;
67 u16 fc_encap_type;
68 };
69
70 struct fib6_node {
71 struct fib6_node __rcu *parent;
72 struct fib6_node __rcu *left;
73 struct fib6_node __rcu *right;
74 #ifdef CONFIG_IPV6_SUBTREES
75 struct fib6_node __rcu *subtree;
76 #endif
77 struct fib6_info __rcu *leaf;
78
79 __u16 fn_bit; /* bit key */
80 __u16 fn_flags;
81 int fn_sernum;
82 struct fib6_info __rcu *rr_ptr;
83 struct rcu_head rcu;
84 };
85
86 struct fib6_gc_args {
87 int timeout;
88 int more;
89 };
90
91 #ifndef CONFIG_IPV6_SUBTREES
92 #define FIB6_SUBTREE(fn) NULL
93 #else
94 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
95 #endif
96
97 /*
98 * routing information
99 *
100 */
101
102 struct rt6key {
103 struct in6_addr addr;
104 int plen;
105 };
106
107 struct fib6_table;
108
109 struct rt6_exception_bucket {
110 struct hlist_head chain;
111 int depth;
112 };
113
114 struct rt6_exception {
115 struct hlist_node hlist;
116 struct rt6_info *rt6i;
117 unsigned long stamp;
118 struct rcu_head rcu;
119 };
120
121 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
122 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
123 #define FIB6_MAX_DEPTH 5
124
125 struct fib6_nh {
126 struct fib_nh_common nh_common;
127
128 #ifdef CONFIG_IPV6_ROUTER_PREF
129 unsigned long last_probe;
130 #endif
131
132 struct rt6_info * __percpu *rt6i_pcpu;
133 struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
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 union {
147 struct list_head fib6_siblings;
148 struct list_head nh_list;
149 };
150 unsigned int fib6_nsiblings;
151
152 refcount_t fib6_ref;
153 unsigned long expires;
154 struct dst_metrics *fib6_metrics;
155 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
156
157 struct rt6key fib6_dst;
158 u32 fib6_flags;
159 struct rt6key fib6_src;
160 struct rt6key fib6_prefsrc;
161
162 u32 fib6_metric;
163 u8 fib6_protocol;
164 u8 fib6_type;
165 u8 should_flush:1,
166 dst_nocount:1,
167 dst_nopolicy:1,
168 dst_host:1,
169 fib6_destroying:1,
170 unused:3;
171
172 struct rcu_head rcu;
173 struct nexthop *nh;
174 struct fib6_nh fib6_nh[0];
175 };
176
177 struct rt6_info {
178 struct dst_entry dst;
179 struct fib6_info __rcu *from;
180 int sernum;
181
182 struct rt6key rt6i_dst;
183 struct rt6key rt6i_src;
184 struct in6_addr rt6i_gateway;
185 struct inet6_dev *rt6i_idev;
186 u32 rt6i_flags;
187
188 struct list_head rt6i_uncached;
189 struct uncached_list *rt6i_uncached_list;
190
191 /* more non-fragment space at head required */
192 unsigned short rt6i_nfheader_len;
193 };
194
195 struct fib6_result {
196 struct fib6_nh *nh;
197 struct fib6_info *f6i;
198 u32 fib6_flags;
199 u8 fib6_type;
200 struct rt6_info *rt6;
201 };
202
203 #define for_each_fib6_node_rt_rcu(fn) \
204 for (rt = rcu_dereference((fn)->leaf); rt; \
205 rt = rcu_dereference(rt->fib6_next))
206
207 #define for_each_fib6_walker_rt(w) \
208 for (rt = (w)->leaf; rt; \
209 rt = rcu_dereference_protected(rt->fib6_next, 1))
210
ip6_dst_idev(struct dst_entry * dst)211 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
212 {
213 return ((struct rt6_info *)dst)->rt6i_idev;
214 }
215
fib6_clean_expires(struct fib6_info * f6i)216 static inline void fib6_clean_expires(struct fib6_info *f6i)
217 {
218 f6i->fib6_flags &= ~RTF_EXPIRES;
219 f6i->expires = 0;
220 }
221
fib6_set_expires(struct fib6_info * f6i,unsigned long expires)222 static inline void fib6_set_expires(struct fib6_info *f6i,
223 unsigned long expires)
224 {
225 f6i->expires = expires;
226 f6i->fib6_flags |= RTF_EXPIRES;
227 }
228
fib6_check_expired(const struct fib6_info * f6i)229 static inline bool fib6_check_expired(const struct fib6_info *f6i)
230 {
231 if (f6i->fib6_flags & RTF_EXPIRES)
232 return time_after(jiffies, f6i->expires);
233 return false;
234 }
235
236 /* Function to safely get fn->sernum for passed in rt
237 * and store result in passed in cookie.
238 * Return true if we can get cookie safely
239 * Return false if not
240 */
fib6_get_cookie_safe(const struct fib6_info * f6i,u32 * cookie)241 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
242 u32 *cookie)
243 {
244 struct fib6_node *fn;
245 bool status = false;
246
247 fn = rcu_dereference(f6i->fib6_node);
248
249 if (fn) {
250 *cookie = READ_ONCE(fn->fn_sernum);
251 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
252 smp_rmb();
253 status = true;
254 }
255
256 return status;
257 }
258
rt6_get_cookie(const struct rt6_info * rt)259 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
260 {
261 struct fib6_info *from;
262 u32 cookie = 0;
263
264 if (rt->sernum)
265 return rt->sernum;
266
267 rcu_read_lock();
268
269 from = rcu_dereference(rt->from);
270 if (from)
271 fib6_get_cookie_safe(from, &cookie);
272
273 rcu_read_unlock();
274
275 return cookie;
276 }
277
ip6_rt_put(struct rt6_info * rt)278 static inline void ip6_rt_put(struct rt6_info *rt)
279 {
280 /* dst_release() accepts a NULL parameter.
281 * We rely on dst being first structure in struct rt6_info
282 */
283 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
284 dst_release(&rt->dst);
285 }
286
287 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
288 void fib6_info_destroy_rcu(struct rcu_head *head);
289
fib6_info_hold(struct fib6_info * f6i)290 static inline void fib6_info_hold(struct fib6_info *f6i)
291 {
292 refcount_inc(&f6i->fib6_ref);
293 }
294
fib6_info_hold_safe(struct fib6_info * f6i)295 static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
296 {
297 return refcount_inc_not_zero(&f6i->fib6_ref);
298 }
299
fib6_info_release(struct fib6_info * f6i)300 static inline void fib6_info_release(struct fib6_info *f6i)
301 {
302 if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
303 call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
304 }
305
306 enum fib6_walk_state {
307 #ifdef CONFIG_IPV6_SUBTREES
308 FWS_S,
309 #endif
310 FWS_L,
311 FWS_R,
312 FWS_C,
313 FWS_U
314 };
315
316 struct fib6_walker {
317 struct list_head lh;
318 struct fib6_node *root, *node;
319 struct fib6_info *leaf;
320 enum fib6_walk_state state;
321 unsigned int skip;
322 unsigned int count;
323 unsigned int skip_in_node;
324 int (*func)(struct fib6_walker *);
325 void *args;
326 };
327
328 struct rt6_statistics {
329 __u32 fib_nodes; /* all fib6 nodes */
330 __u32 fib_route_nodes; /* intermediate nodes */
331 __u32 fib_rt_entries; /* rt entries in fib table */
332 __u32 fib_rt_cache; /* cached rt entries in exception table */
333 __u32 fib_discarded_routes; /* total number of routes delete */
334
335 /* The following stats are not protected by any lock */
336 atomic_t fib_rt_alloc; /* total number of routes alloced */
337 atomic_t fib_rt_uncache; /* rt entries in uncached list */
338 };
339
340 #define RTN_TL_ROOT 0x0001
341 #define RTN_ROOT 0x0002 /* tree root node */
342 #define RTN_RTINFO 0x0004 /* node with valid routing info */
343
344 /*
345 * priority levels (or metrics)
346 *
347 */
348
349
350 struct fib6_table {
351 struct hlist_node tb6_hlist;
352 u32 tb6_id;
353 spinlock_t tb6_lock;
354 struct fib6_node tb6_root;
355 struct inet_peer_base tb6_peers;
356 unsigned int flags;
357 unsigned int fib_seq;
358 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
359 };
360
361 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
362 #define RT6_TABLE_MAIN RT_TABLE_MAIN
363 #define RT6_TABLE_DFLT RT6_TABLE_MAIN
364 #define RT6_TABLE_INFO RT6_TABLE_MAIN
365 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN
366
367 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
368 #define FIB6_TABLE_MIN 1
369 #define FIB6_TABLE_MAX RT_TABLE_MAX
370 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL
371 #else
372 #define FIB6_TABLE_MIN RT_TABLE_MAIN
373 #define FIB6_TABLE_MAX FIB6_TABLE_MIN
374 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN
375 #endif
376
377 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
378 struct fib6_table *,
379 struct flowi6 *,
380 const struct sk_buff *, int);
381
382 struct fib6_entry_notifier_info {
383 struct fib_notifier_info info; /* must be first */
384 struct fib6_info *rt;
385 unsigned int nsiblings;
386 };
387
388 /*
389 * exported functions
390 */
391
392 struct fib6_table *fib6_get_table(struct net *net, u32 id);
393 struct fib6_table *fib6_new_table(struct net *net, u32 id);
394 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
395 const struct sk_buff *skb,
396 int flags, pol_lookup_t lookup);
397
398 /* called with rcu lock held; can return error pointer
399 * caller needs to select path
400 */
401 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
402 struct fib6_result *res, int flags);
403
404 /* called with rcu lock held; caller needs to select path */
405 int fib6_table_lookup(struct net *net, struct fib6_table *table,
406 int oif, struct flowi6 *fl6, struct fib6_result *res,
407 int strict);
408
409 void fib6_select_path(const struct net *net, struct fib6_result *res,
410 struct flowi6 *fl6, int oif, bool have_oif_match,
411 const struct sk_buff *skb, int strict);
412 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
413 const struct in6_addr *daddr,
414 const struct in6_addr *saddr);
415
416 struct fib6_node *fib6_locate(struct fib6_node *root,
417 const struct in6_addr *daddr, int dst_len,
418 const struct in6_addr *saddr, int src_len,
419 bool exact_match);
420
421 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
422 void *arg);
423 void fib6_clean_all_skip_notify(struct net *net,
424 int (*func)(struct fib6_info *, void *arg),
425 void *arg);
426
427 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
428 struct nl_info *info, struct netlink_ext_ack *extack);
429 int fib6_del(struct fib6_info *rt, struct nl_info *info);
430
431 static inline
rt6_get_prefsrc(const struct rt6_info * rt,struct in6_addr * addr)432 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
433 {
434 const struct fib6_info *from;
435
436 rcu_read_lock();
437
438 from = rcu_dereference(rt->from);
439 if (from) {
440 *addr = from->fib6_prefsrc.addr;
441 } else {
442 struct in6_addr in6_zero = {};
443
444 *addr = in6_zero;
445 }
446
447 rcu_read_unlock();
448 }
449
450 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
451 struct fib6_config *cfg, gfp_t gfp_flags,
452 struct netlink_ext_ack *extack);
453 void fib6_nh_release(struct fib6_nh *fib6_nh);
454
455 int call_fib6_entry_notifiers(struct net *net,
456 enum fib_event_type event_type,
457 struct fib6_info *rt,
458 struct netlink_ext_ack *extack);
459 int call_fib6_multipath_entry_notifiers(struct net *net,
460 enum fib_event_type event_type,
461 struct fib6_info *rt,
462 unsigned int nsiblings,
463 struct netlink_ext_ack *extack);
464 void fib6_rt_update(struct net *net, struct fib6_info *rt,
465 struct nl_info *info);
466 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
467 unsigned int flags);
468
469 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
470
471 void fib6_gc_cleanup(void);
472
473 int fib6_init(void);
474
475 struct ipv6_route_iter {
476 struct seq_net_private p;
477 struct fib6_walker w;
478 loff_t skip;
479 struct fib6_table *tbl;
480 int sernum;
481 };
482
483 extern const struct seq_operations ipv6_route_seq_ops;
484
485 int call_fib6_notifier(struct notifier_block *nb, struct net *net,
486 enum fib_event_type event_type,
487 struct fib_notifier_info *info);
488 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
489 struct fib_notifier_info *info);
490
491 int __net_init fib6_notifier_init(struct net *net);
492 void __net_exit fib6_notifier_exit(struct net *net);
493
494 unsigned int fib6_tables_seq_read(struct net *net);
495 int fib6_tables_dump(struct net *net, struct notifier_block *nb);
496
497 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
498 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
499 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
500
501 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
fib6_metric_locked(struct fib6_info * f6i,int metric)502 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
503 {
504 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
505 }
506
507 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
508 int fib6_rules_init(void);
509 void fib6_rules_cleanup(void);
510 bool fib6_rule_default(const struct fib_rule *rule);
511 int fib6_rules_dump(struct net *net, struct notifier_block *nb);
512 unsigned int fib6_rules_seq_read(struct net *net);
513
fib6_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi6 * fl6,struct flow_keys * flkeys)514 static inline bool fib6_rules_early_flow_dissect(struct net *net,
515 struct sk_buff *skb,
516 struct flowi6 *fl6,
517 struct flow_keys *flkeys)
518 {
519 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
520
521 if (!net->ipv6.fib6_rules_require_fldissect)
522 return false;
523
524 skb_flow_dissect_flow_keys(skb, flkeys, flag);
525 fl6->fl6_sport = flkeys->ports.src;
526 fl6->fl6_dport = flkeys->ports.dst;
527 fl6->flowi6_proto = flkeys->basic.ip_proto;
528
529 return true;
530 }
531 #else
fib6_rules_init(void)532 static inline int fib6_rules_init(void)
533 {
534 return 0;
535 }
fib6_rules_cleanup(void)536 static inline void fib6_rules_cleanup(void)
537 {
538 return ;
539 }
fib6_rule_default(const struct fib_rule * rule)540 static inline bool fib6_rule_default(const struct fib_rule *rule)
541 {
542 return true;
543 }
fib6_rules_dump(struct net * net,struct notifier_block * nb)544 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb)
545 {
546 return 0;
547 }
fib6_rules_seq_read(struct net * net)548 static inline unsigned int fib6_rules_seq_read(struct net *net)
549 {
550 return 0;
551 }
fib6_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi6 * fl6,struct flow_keys * flkeys)552 static inline bool fib6_rules_early_flow_dissect(struct net *net,
553 struct sk_buff *skb,
554 struct flowi6 *fl6,
555 struct flow_keys *flkeys)
556 {
557 return false;
558 }
559 #endif
560 #endif
561